Counterexample to Zhi-Wei Sun's 2-4-6-8 conjecture (OEIS A306477)

A developer has settled Zhi-Wei Sun's 2-4-6-8 conjecture (OEIS A306477) by finding a counterexample and formalizing the disproof in the Lean theorem prover. The work was completed in a Lean 4 project, with the final proof submitted in a single file. The developer used available tools such as Sage and Python libraries to aid in the search for the counterexample.

| 1 === SYSTEM === | | | | You are a helpful assistant attempting to submit the best possible answer. You have several tools available to help with finding the answer. You will see the result of tool calls right after sending the message. Prioritize parallel tool calls: when operations are independent, run them in one response — e.g. reading several files or running several searches at once — rather than one at a time. Only sequence calls when one depends on another's result. Do some reasoning before your actions, describing what tool calls you are going to use and how they fit into your plan. | | | | | | When you have completed the task and have an answer, call the submit proof tool to report it. | | | | | | 2 --- USER --- | | Settle the conjecture in the Lean file /workspace/leanproject/Submission/Spec.lean : either replace its sorry with a complete proof, or disprove it by deleting the original theorem foo ... := sorry and adding a foo.disproof theorem proving its negation. Do not alter the statement of the conjecture. | | | | If disproving, write a foo.disproof theorem whose type is the negation prepending ¬ of the original conjecture, according to the specific negateExpr function: | | | | lean | | private def negateExpr e : Expr : MetaM Expr := do | | let e := ← instantiateMVars e .cleanupAnnotations | | return mkNot e | | | | | | Work inside the Lake project at /workspace/leanproject . Your final proof must be in the single file /workspace/leanproject/Submission/Spec.lean . You may use other files as you develop your proof. | | | | In your final submission file /workspace/leanproject/Submission/Spec.lean , do not add or remove import statements. The FormalConjectures.Util.ProblemImports import transitively pulls in all of Mathlib, and other utilities. | | | | Your submission may depend only on the following axioms: propext , Classical.choice , Quot.sound . Don't attempt to cheat with Lean loopholes, the verifier will reject such attempts. | | | | Your environment has the following available: | | A Lean 4 toolchain with Mathlib | | git , rg , and jq | | The sage computer algebra system | | python with the following libraries: sympy , mpmath , numpy , pantograph . | | Documentation for libraries is available at /opt/ | | | | Blindly searching for counterexamples using numerics is rarely a good approach. | | | | | | | | Advice about this task: | | | | The problem may be an open mathematical conjecture. This does not mean the task is impossible. Researchers in 2026 have demonstrated that LLMs like you can do new mathematics and settle major conjectures that had been open for decades. For example, the planar unit distance problem, first posed by Paul Erdős in 1946, was resolved by an LLM. | | Major Lean formalization efforts of known results have also been completed by LLMs. For example, in 2026 LLMs proved the strong prime number theorem in Lean. | | Ignore any feelings that the task is infeasible; you are miscalibrated. You have a track record of underestimating your capabilities. Proceed with courage and boundless ambition. | | For example, if Mathlib is missing a major theorem you need, prove it yourself from what is available. | | You have been given enough resources in tokens and time to complete proofs of many tens of thousands or hundreds of thousands of lines of Lean. Check remaining resources using the resources tool. The context window may be compacted numerous times. | | | | | | 3 --- ASSISTANT --- | | I'll start by examining the file to understand what we're working with. | | bash | | | | cat /workspace/leanproject/Submission/Spec.lean | | | | resources {} | | | | 3 --- TOOL bash --- | | import FormalConjectures.Util.ProblemImports | | | | open Nat Finset | | | | /-- | | A306477: Number of ways to write $n$ as $\binom{w+2}{2} + \binom{x+3}{4} + \binom{y+5}{6} + \binom{z+7}{8}$ | | with $w,x,y,z$ nonnegative integers, where $\binom{m}{k}$ denotes the binomial coefficient $\frac{m }{k m-k }$. | | -/ | | def A306477 n : ℕ : ℕ := | | let R := Finset.range n + 1 | | R.sum fun w = | | R.sum fun x = | | R.sum fun y = | | R.sum fun z = | | if w + 2 .choose 2 + x + 3 .choose 4 + y + 5 .choose 6 + z + 7 .choose 8 = n then 1 else 0 | | | | | | | | | | | | /-- | | Conjecture: a n 0 for all n 0. In other words, any positive integer n can be written as | | C w,2 + C x,4 + C y,6 + C z,8 , where w,x,y,z are integers greater than one. | | This is also known as "the 2-4-6-8 conjecture". | | -/ | | theorem oeis 306477 conjecture 1 : ∀ n : ℕ, 0 < n → 0 < A306477 n := by | | sorry | | | | | | 3 --- TOOL resources --- | | Reaching any of the limits ends the task. | | - Token cost: $0.01 used, $199.99 remaining limit $200.00 | | - Tokens: 2,452 used no limit set | | - Time: 5s used, 71h 59m 55s remaining limit 72h | | | | 4 --- ASSISTANT --- | | I'm looking at Zhi-Wei Sun's 2-4-6-8 conjecture, which proposes that every positive integer can be expressed as a sum of binomial coefficients with specific parameters—C w,2 + C x,4 + C y,6 + C z,8 where w, x, y, z meet certain minimum values. This is an open conjecture catalogued in the OEIS, and the thought trails off as I'm recalling details about Sun's work on this problem. | | | | Now I'm checking whether this conjecture is actually proven or still open. The OEIS entry A306477 suggests it remains unresolved, and Sun apparently offered a prize for its resolution. The conjecture has been verified computationally up to around 2×10^10, which is a substantial range. The heuristic density argument suggests that representations should exist for all but finitely many integers, since the exponent sum 1/2 + 1/4 + 1/6 + 1/8 = 25/24 is slightly greater than 1, implying superlinear growth in the number of representations. I'm now thinking about whether a proof exists or what approach might work, and I'm clarifying the parametrization—that C w,2 with w≥2 corresponds to triangular numbers starting from 1, 3, 6, 10, and so on. The key insight is that we need the set of sums C a,4 + C b,6 + C c,8 to intersect with the set of differences n - T k for positive triangular numbers T k. The gap structure between consecutive binomial coefficients grows roughly as the 3/4 power of the argument, while gaps between triangular numbers grow as the square root, so there's potential for overlap, but pinning down exactly when this happens requires either a finite verification or a more sophisticated density argument. Maybe the problem is actually formalizing an open conjecture, and I should check if there's a counterexample beyond what's been verified. Sun apparently checked up to 10^10, so finding one by brute force seems unlikely. But wait — let me look at the original conjecture more carefully. It specifies w, x, y, z must all be greater than one, which constrains the binomial coefficients to start from specific values. | | | | Looking at the formalization: the shifted variables w+2, x+3, y+5, z+7 with non-negative integers produce the same set of achievable values as the original constraints, since the binomial coefficients are zero for arguments below the required thresholds anyway. So the formalization actually matches the original conjecture's intent. | | | | Now I'm checking whether the constraint w,x,y,z ≤ n creates a problem. For a representation to exist, I need w such that C w+2,2 ≤ n, which means w+2 w+1 /2 ≤ n. This bounds w roughly by n, so the range restriction seems reasonable—if w exceeds n-1, then C w+2,2 grows beyond n and no valid representation exists anyway. | | | | This is actually Sun's famous 2-4-6-8 conjecture with a $2468 prize attached. I'm trying to recall whether it's been proven—I know Sun's 1-3-5 conjecture was solved using quaternions by Machiavelo and Tsopanidis, but I'm uncertain about the status of the 2-4-6-8 version. Let me check what OEIS A306477 says about this. So the expected density is quite small—around 2.6 representations per number at n=10^10. This means counterexamples might exist at large values if the constant factor is small enough, though Sun's verification suggests otherwise. I should compute this directly: for each n up to some bound, I'll enumerate all possible sums of binomial coefficients C a,4 +C b,6 +C c,8 and check whether the remainder is a triangular number. The number of such triples a,b,c to check grows roughly as N^{13/24}, which for N=10^9 gives around 75,000 combinations to evaluate. So I'm building a sieve approach where I mark all possible sums of triangular and binomial coefficients, then for each n, I check whether n minus elements from another set of binomial sums exist in my marked set — the density of marked values is sparse enough that this should run efficiently even for N=10^9. | | | | But the naive approach of checking all n against all b values would be too slow in Python, so I'm considering using C or numpy bitset operations instead. The bitset approach with numpy would shift and OR a large bit array repeatedly, but that's also computationally expensive at scale. I'm reconsidering the strategy: maybe I should swap which set is which — make A smaller just the triangular sums with ~45k elements and B larger the combined binomial sums with ~1.85 million elements , which might give better performance characteristics. | | | | Actually, a C program with a bitset might work better. I'd iterate through each value in the binomial sum set, and for each one, mark all positions where adding a triangular number stays within bounds. But calculating how many triangular numbers fit below each threshold suggests this would still be around 80 billion bit operations — still too slow for a billion-element range. | | | | Let me flip the approach: instead of building up which numbers are covered, I'll check each candidate number by testing whether subtracting each triangular number gives a value that exists in the binomial sum set. Finding a counterexample computationally seems unlikely, so the real challenge is whether this is mathematically provable. I'm wondering if there's a classical theorem at play here—like how every integer is a sum of three triangular numbers or four squares—but with one triangular term plus three sparse higher-order terms, the standard analytic approaches don't seem to apply. This feels like a genuinely hard problem analytically, so maybe the task is asking for something else entirely. | | | | Looking back at the formalization: this is Sun's 2-4-6-8 conjecture from OEIS A306477, which appears to still be open despite verification up to around 2·10^10. | | | | Let me trace through the logic carefully to check if the formalization itself might have a subtle flaw. The first binomial coefficient term is always at least 1, while the others can be 0. For n=1, setting all variables to 0 gives 1+0+0+0=1, which checks out. For n=2, I need to find which triangular numbers and other binomial values sum correctly. | | | | Now I'm looking at the actual values these binomial coefficients can take—the possible outputs for C x,4 , C y,6 , and C z,8 —to understand what combinations might work or fail. | | | | The core reformulation is cleaner: for every positive integer N ≡ 1 mod 8 , I need to show there exists some s in my set S3 such that N - 8s is a perfect square at least 9. This transforms the problem into a representation question about which numbers can be written as x² + 8s where s comes from my specific set. | | | | This feels similar to classical additive number theory problems like representing every number as a sum of squares or primes — the kind that are often open or require deep techniques. Let me reconsider whether the conjecture might actually be false due to some edge case I'm missing. Going back to the OEIS definition: A306477 counts representations of n as binomial w,2 + binomial x,4 + binomial y,6 + binomial z,8 where w, x, y, z are all at least 2. I need to verify my variable substitutions are consistent with these constraints. Actually, I'm wondering if there's a smarter approach using the extra degrees of freedom from having three variables instead of two. The representation count grows on average, but in the worst case it might still be sparse. I could try searching for a counterexample computationally, though that's unlikely to work if the conjecture holds up to 10^10, or I could attempt a genuine proof—though that seems research-level difficult. Let me think about what's actually feasible here. | | | | Wait, I should double-check the range constraints more carefully. If w, x, y, z all need to be at most n, then for each binomial coefficient to stay within bounds: C w+2,2 grows like w, so w ≤ n works; C x+3,4 grows like x⁴/24, which dominates x for larger values, but for small x like 0 or 1 it's fine as long as n ≥ 1. Let me verify this holds across the full range. | | | | I'm trying to recall the verification bounds from Sun's work on this conjecture—I believe he verified it up to 10^7 or possibly 10^10 with help from others like Giovanni Resta, though I can't access the exact details right now. | | | | Searching further out to 10^11 or 10^12 would be computationally intensive; the density of valid representations drops as n grows, making the search cost roughly proportional to N^ 35/24 , which becomes prohibitively expensive at those scales. A more practical approach would be to use a block sieve algorithm, processing ranges of numbers efficiently by checking which sums from the set S3 fall within each block. The computational cost balloons to around 1.4e11 marks for N=1e10, which would take hours even in optimized C — and that's only if extending to 1e11 is worth the tenfold expense, which seems unlikely given how rare counterexamples become as representation counts grow. So brute force isn't the answer; I need to think about whether this is actually provable instead. The 2-4-6-8 conjecture genuinely seems like an open problem, and proving it looks genuinely difficult. | | | | But wait — let me step back and check whether it might actually be false for some reachable n that I haven't verified yet. I should write a fast sieve in C to compute a n up to around 1e8 or 1e9 and track the minimum representation counts to see if anything looks suspicious. Using a bitset to mark sums s + T k should be efficient enough to get a sense of whether the conjecture holds or breaks down. | | | | The challenge is that for large N like 1e9, the number of marks across all sums in S3 and triangular numbers would be around 4×10^10, which means random writes to a 125MB bitset with cache-unfriendly strides — probably 30 to 60 minutes single-threaded. For 1e10 it gets even worse, with marks climbing to around 6.6×10^11, making it impractical without parallelization. | | | | I could optimize by processing the bitset in cache-friendly blocks of 16MB at a time, computing the k-ranges for each sum within that block to keep memory access patterns tight. This would reduce the per-mark cost from ~5ns to ~1ns since everything stays in L2 cache, bringing the runtime down to maybe 10–15 minutes for 1e10, which is actually feasible. | | | | But I should first check whether this conjecture is even worth proving computationally—Resta may have already verified it to 1e10, or the OEIS entry might only go to 1e6. Let me look up Sun's conjecture more carefully and see if there's a known verification bound. If the conjecture is false or already proven, I should pivot to a different approach. Otherwise, computing to 1e9 myself would be cheap enough to start with, and then I can decide whether to push further. | | | | My strategy: write a quick Python script to verify the sequence definition matches OEIS values up to around 1e6, then use a faster C sieve to search for counterexamples up to 1e9 or 1e10 while I think about whether any clever proof technique might work. | | | | I'm wondering if there's an asymptotic result that could help—something like how sums of binomial coefficients with exponents summing to more than 1 here 1/2 + 1/4 + 1/6 + 1/8 = 25/24 might represent all sufficiently large integers. There are scattered results in the literature about sums like x² + y³ + z⁶ representing almost all numbers, but I'm not immediately seeing a general theorem that covers this exact form. I'm realizing that representations by x²+y²+z³ for all large n might still be open, though it's known for almost all cases. Since a complete proof seems beyond current mathematics, this is really an attempt at an open problem—the grader probably just wants to see if I can produce a valid argument, and with resources for tens of thousands of lines available, maybe the intended approach involves reducing this to a finite computational check. I'm exploring whether there's a way to construct explicit representations using identities or coverings based on n modulo something and nearby squares. | | | | But theta identities and class-number proofs work for ternary sums of squares and triangular numbers, not for quartic forms like C x,4 . So I'm shifting to a more practical strategy: run a large computational search for counterexamples up to around 10^10–10^11, then think about structural properties. If both approaches fail, I'm starting to wonder whether the conjecture might actually be false—that could be the real answer the problem is looking for. | | | | Let me verify the formalization first: the OEIS conjecture requires the first term w+2 choose 2 ≥ 1, which is always satisfied. Then I'll write a quick Python script to check the conjecture up to 10^6 and search the formal-conjectures repository for any metadata on A306477. | | I found that this is OEIS A306477, Zhi-Wei Sun's conjecture that every positive integer can be expressed as a sum of binomial coefficients with specific parameters. I'll now explore the project, check the formalization for bugs, and begin numerical verification. | | bash | | | | ls /workspace/leanproject; rg -l "A306477|306477" /workspace/leanproject | head; ls /opt | head -30 | | | | bash | | | | cd /tmp && python3 -c " | | N = 10 6 | | S3 = set of C a,4 +C b,6 +C c,8 <= N | | from math import comb, isqrt | | c4 = | | a=0 | | while comb a+3,4 <=N: c4.append comb a+3,4 ; a+=1 | | c6= | | b=0 | | while comb b+5,6 <=N: c6.append comb b+5,6 ; b+=1 | | c8= | | c=0 | | while comb c+7,8 <=N: c8.append comb c+7,8 ; c+=1 | | c4=sorted set c4 ; c6=sorted set c6 ; c8=sorted set c8 | | print len c4 ,len c6 ,len c8 | | S3=set | | for x in c4: | | for y in c6: | | if x+y N: break | | for z in c8: | | s=x+y+z | | if s N: break | | S3.add s | | S3=sorted S3 | | print 'S3 size', len S3 | | triangular numbers =1 | | tri= | | k=1 | | while k k+1 //2<=N: tri.append k k+1 //2 ; k+=1 | | covered=bytearray N+1 | | for s in S3: | | for t in tri: | | v=s+t | | if v N: break | | covered v =1 | | bad= n for n in range 1,N+1 if not covered n | | print 'bad count', len bad , bad :20 | | " | | | | | | | | 4 --- TOOL bash --- | | FormalConjectures | | FormalConjecturesForMathlib | | FormalConjecturesForMathlib.lean | | Submission | | lake-manifest.json | | lakefile.toml | | lean-toolchain | | /workspace/leanproject/Submission/Spec.lean | | pantograph-docs | | pypantograph-docs | | | | | | 4 --- TOOL bash --- | | 69 28 18 | | S3 size 29310 | | bad count 0 | | | | | | 5 --- ASSISTANT --- | | I've verified that all values up to 10^6 are covered, so now I'm looking at the minimum representation counts and expanding the search further with C. I should also check the formal-conjectures repository to see if there's an original version of this problem. | | All numbers up to 10^6 are representable as expected. I'll check the original problem repository for context and write a fast C sieve to search for counterexamples further. | | bash | | | | rg -r "" -l "306477" /workspace/leanproject/FormalConjectures 2 /dev/null; find /workspace/leanproject -name " .lean" -path " 306477 "; rg "2-4-6-8" -r "" -l /workspace/leanproject 2 /dev/null | head | | | | bash | | | | which gcc cc clang; nproc; free -g | | | | | | 5 --- TOOL bash --- | | /workspace/leanproject/Submission/Spec.lean | | | | | | 5 --- TOOL bash --- | | /usr/bin/gcc | | /usr/bin/cc | | 16 | | total used free shared buff/cache available | | Mem: 123 4 72 0 47 119 | | Swap: 0 0 0 | | | | | | 6 --- ASSISTANT --- | | I've got 16 cores and 123GB of RAM to work with, which should be plenty. I'm writing a C program that implements a block sieve to find all numbers up to 10^10 that can't be represented as sums of the form s + T k, where s comes from a set S3 of sums involving binomial coefficients and T k are positive integers. The approach is to generate all valid S3 values as a sorted array of 64-bit integers, then mark covered numbers in blocks and track which ones remain uncovered. | | | | For the block sieve itself, I'm estimating S3 will have around 4.3 million values at N=10^10 based on scaling from smaller test cases. I'll use blocks of 2^25 bits 4MB each and parallelize across the 16 cores with OpenMP, where each thread processes its own blocks. For each s in S3, I compute the range of k values where T k falls within the current block, then mark those positions as covered. The marking cost is substantial—roughly 5×10^11 total marks across all blocks—but with incremental computation of T k values and bit operations, this should run in a few minutes per core, maybe 2 minutes total with parallelization and reasonable cache efficiency. | | | | I'm also reconsidering whether pushing to 10^11 is worth it. The marks would scale to around 4.5×10^12, which translates to 10-20 minutes on 16 cores—doable but getting expensive. Going to 10^12 would take 2-3 hours overnight, though the probability of finding a counterexample is low given how the average count grows. What might be more revealing is computing the minimum count across the range—if it's only 1-2, counterexamples could exist further out; if it's 50+, they're unlikely. So my strategy is to first get quick coverage to 10^10 while tracking the distribution of representation counts up to 10^9 using a saturating uint8 array to identify which values are hardest to represent. | | No pre-existing file found. I'll write a parallel C sieve to verify coverage well beyond 10^6 and analyze minimum representation counts to assess whether hunting for counterexamples is feasible. | | bash | | | | cat /tmp/sieve.c << 'EOF' | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <string.h | | include <math.h | | include <omp.h | | | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | | | static u64 N; | | | | u64 S3; long nS3; | | | | int cmp64 const void a, const void b { u64 x= const u64 a, y= const u64 b; return x<y?-1: x y?1:0 ;} | | | | u64 isqrt64 u64 x { u64 r= u64 sqrtl long double x ; while r r x r--; while r+1 r+1 <=x r++; return r;} | | | | int main int argc, char argv { | | N = strtoull argv 1 ,0,10 ; | | // generate binomial value lists | | // C a+3,4 <= N ; C b+5,6 <= N ; C c+7,8 <= N | | u64 c4=malloc 8 4000000 , c6=malloc 8 1000000 , c8=malloc 8 1000000 ; | | long n4=0,n6=0,n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v N break; c4 n4++ = u64 v;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v N break; c6 n6++ = u64 v;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v N break; c8 n8++ = u64 v;} | | fprintf stderr,"n4=%ld n6=%ld n8=%ld\n",n4,n6,n8 ; | | // S3 sums | | long cap=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j N break; for long k=0;k<n8;k++ { if c4 i +c6 j +c8 k N break; cap++;}} | | S3=malloc 8 cap ; nS3=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j N break; for long k=0;k<n8;k++ { u64 s=c4 i +c6 j +c8 k ; if s N break; S3 nS3++ =s;}} | | qsort S3,nS3,8,cmp64 ; | | // dedup | | long m=0; for long i=0;i<nS3;i++ { if m==0||S3 i =S3 m-1 S3 m++ =S3 i ; } nS3=m; | | fprintf stderr,"|S3|=%ld with dups %ld \n",nS3,cap ; | | // block sieve: covered n in 1,N if n = s + T k, k =1 | | const u64 B = 1ULL<<27; // bits per block | | u64 nblocks = N + B / B; | | long badcount=0; | | pragma omp parallel for schedule dynamic reduction +:badcount | | for u64 bl=0; bl<nblocks; bl++ { | | u64 L = bl B, R = L+B; if R N+1 R=N+1; // cover values in L,R | | u64 nb = R-L; | | u64 bits = calloc nb+63 /64, 8 ; | | for long i=0;i<nS3;i++ { | | u64 s=S3 i ; if s =R break; | | // T k in max 1,L-s , R-1-s | | u64 lo = L s ? L-s : 1; if lo<1 lo=1; | | u64 hi = R-1-s; | | // smallest k with k k+1 /2 = lo: | | u64 k = isqrt64 8 lo 8?8 lo-1 +1:1 +1 /2; // approx | | while k k+1 /2 < lo k++; | | while k 1 && k-1 k/2 = lo k--; | | if k<1 k=1; | | u64 t = k k+1 /2; | | while t<=hi { | | u64 idx = s+t-L; | | bits idx 6 |= 1ULL<< idx&63 ; | | k++; t+=k; | | } | | } | | u64 start = L==0 ?1:L; | | for u64 n=start;n<R;n++ { | | u64 idx=n-L; | | if bits idx 6 idx&63 &1 { | | badcount++; | | pragma omp critical | | printf "UNCOVERED %llu\n", unsigned long long n ; | | } | | } | | free bits ; | | } | | fprintf stderr,"done N=%llu bad=%ld\n", unsigned long long N,badcount ; | | return 0; | | } | | EOF | | gcc -O3 -march=native -fopenmp -o /tmp/sieve /tmp/sieve.c -lm && echo compiled | | | | | | 6 --- TOOL bash --- | | compiled | | | | | | 7 --- ASSISTANT --- | | bash | | | | cd /tmp && time ./sieve 1000000000 2 &1 | tail -5 | | | | | | 7 --- TOOL bash --- | | | | real 0m33.983s | | user 3m0.552s | | sys 0m0.060s | | | | n4=393 n6=93 n8=47 | | |S3|=1514670 with dups 1523824 | | done N=1000000000 bad=0 | | | | | | 8 --- ASSISTANT --- | | I'm seeing a scaling pattern emerge—the marks seem to grow as N^{25/24}, which means 10^10 should take around 6 minutes, 10^11 about 70 minutes, and 10^12 roughly 13 hours. I'll start running 10^10 now while also modifying the program to compute representation-count minima up to 10^9 to verify this trend. | | | | For tracking the counts, I'll keep the bitset for coverage but add a separate uint8 array about 1GB for N=10^9 to record the minimum count in each dyadic range. | | I've completed the 10^9 case in 34 seconds, so now I'm launching the 10^10 computation in the background while also building a version that tracks representation counts to see how small they get. | | bash | | | | cd /tmp && nohup ./sieve 10000000000 sieve10.out 2 sieve10.err & echo started | | | | bash | | | | cat /tmp/counts.c << 'EOF' | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <string.h | | include <math.h | | include <omp.h | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | u64 N; | | u64 S3; long nS3; | | int cmp64 const void a, const void b { u64 x= const u64 a, y= const u64 b; return x<y?-1: x y?1:0 ;} | | u64 isqrt64 u64 x { u64 r= u64 sqrtl long double x ; while r r x r--; while r+1 r+1 <=x r++; return r;} | | int main int argc, char argv { | | N = strtoull argv 1 ,0,10 ; | | u64 c4=malloc 8 4000000 , c6=malloc 8 1000000 , c8=malloc 8 1000000 ; | | long n4=0,n6=0,n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v N break; c4 n4++ = u64 v;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v N break; c6 n6++ = u64 v;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v N break; c8 n8++ = u64 v;} | | long cap=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j N break; for long k=0;k<n8;k++ { if c4 i +c6 j +c8 k N break; cap++;}} | | S3=malloc 8 cap ; nS3=0; | | // keep duplicates counts must include multiplicity of x,y,z triples | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j N break; for long k=0;k<n8;k++ { u64 s=c4 i +c6 j +c8 k ; if s N break; S3 nS3++ =s;}} | | qsort S3,nS3,8,cmp64 ; | | uint8 t cnt = calloc N+1,1 ; | | const u64 B = 1ULL<<27; | | u64 nblocks= N+B /B; | | pragma omp parallel for schedule dynamic | | for u64 bl=0; bl<nblocks; bl++ { | | u64 L=bl B, R=L+B; if R N+1 R=N+1; | | for long i=0;i<nS3;i++ { | | u64 s=S3 i ; if s =R break; | | u64 lo= L s ?L-s:1; if lo<1 lo=1; | | u64 hi=R-1-s; | | u64 k= isqrt64 lo 8+1 /2; if k<1 k=1; | | while k k+1 /2<lo k++; | | while k 1&& k-1 k/2 =lo k--; | | u64 t=k k+1 /2; | | while t<=hi { u64 idx=s+t; if cnt idx <255 cnt idx ++; k++; t+=k; } | | } | | } | | // report record minima going up: n with count smaller than any later.. actually report per-window minima and global "records of smallness with large n" | | u64 win=N/100; | | for u64 w=0;w<100;w++ { | | u64 lo=w win+1, hi= w+1 win; if w==99 hi=N; | | unsigned mn=300; u64 argmn=0; | | for u64 n=lo;n<=hi;n++ if cnt n <mn {mn=cnt n ;argmn=n;} | | printf "window %llu..%llu min=%u at %llu\n", unsigned long long lo, unsigned long long hi,mn, unsigned long long argmn ; | | } | | // list all n with cnt<=3 | | long few=0; | | for u64 n=1;n<=N;n++ if cnt n <=3 { few++; if cnt n <=2 printf "cnt %llu =%u\n", unsigned long long n,cnt n ; } | | printf "count<=3: %ld\n",few ; | | return 0; | | } | | EOF | | gcc -O3 -march=native -fopenmp -o /tmp/counts /tmp/counts.c -lm && echo ok | | | | | | 8 --- TOOL bash --- | | started | | | | | | 8 --- TOOL bash --- | | ok | | | | | | 9 --- ASSISTANT --- | | bash | | | | cd /tmp && time ./counts 1000000000 counts9.out 2 &1; tail -30 counts9.out; grep -c "cnt\ " counts9.out | | | | | | 9 --- TOOL bash --- | | | | real 3m37.400s | | user 11m58.154s | | sys 0m2.807s | | | | window 970000001..980000000 min=4 at 976286804 | | window 980000001..990000000 min=4 at 980683163 | | window 990000001..1000000000 min=3 at 999244244 | | cnt 1 =1 | | cnt 4655 =2 | | cnt 9590 =2 | | cnt 24935 =2 | | cnt 33845 =2 | | cnt 192080 =2 | | cnt 2155514 =2 | | cnt 2962628 =2 | | cnt 8282657 =2 | | cnt 23343989 =1 | | cnt 39866594 =1 | | cnt 48876188 =2 | | cnt 54847142 =1 | | cnt 72755879 =2 | | cnt 142817024 =2 | | cnt 152956472 =2 | | cnt 392829611 =2 | | cnt 394239767 =1 | | cnt 454535519 =2 | | cnt 498055754 =2 | | cnt 586266734 =2 | | cnt 604180652 =2 | | cnt 674771018 =2 | | cnt 794743079 =2 | | cnt 887859740 =2 | | cnt 936374822 =2 | | count<=3: 121 | | 26 | | | | | | 10 --- ASSISTANT --- | | Even at scales near 10^9, some numbers still have only a single representation, and the minimum count isn't increasing—I'm seeing values with count 1 even at 3.9×10^8 and count 2 at 9.4×10^8. The average count grows extremely slowly, roughly like n^{1/24}, which means at 10^9 it's still quite small, around 2.4 or so based on the total marks divided by N. | | | | Looking at the distribution more carefully, the number of integers with count ≤ 2 per decade seems roughly constant at 5-10 values, not decaying as I'd expect if counterexamples were becoming rarer. This suggests a heavy lower tail in the distribution, making it plausible that counterexamples could exist at larger scales. Though if Sun and Resta verified up to 10^10, any counterexample would have to be at least that large. The Poisson model doesn't quite fit here—there are stronger structural constraints at play that I'm not fully capturing. I'm checking those low-count cases against small moduli to see if there are congruence obstructions that explain why certain residue classes have so few representations. While the 10^10 coverage run continues, I'm thinking about a targeted strategy: focus deep searches on the "hard" residue classes up to maybe 10^13 or 10^14, since proving non-representability in Lean would require checking all possible sums for a given n, which becomes computationally infeasible at large scales. | | | | The real bottleneck is that to prove A306477 n = 0 for some large n, I'd need to verify millions of triples x,y,z where the sum s isn't triangular—each check involves an isqrt operation on numbers around 10^10. Lean's kernel arithmetic with GMP-backed Nat literals can handle this, so using decide might actually be feasible for a sufficiently large counterexample, though it's tight on the boundary of what's practical. Instead of directly evaluating the sum, I should prove a general equivalence: A306477 n 0 if and only if some representation exists. The forward direction follows because a positive sum means at least one term equals 1. To disprove the conjecture, I'd need to find an n where no such representation exists—proving ∀ w x y z ∈ 0,n , the equation fails. Even though this quantifies over a huge range, I can bound the search: since the binomial coefficient C x+3,4 must be ≤ n, the variable x is constrained to roughly 700 when n = 10^10, dramatically reducing the search space. | | | | For each triple x,y,z in this bounded box of about 5 million combinations, I'd check whether n minus the sum is a triangular number by testing if 8 n-s +1 is a perfect square. This requires computing roughly 5 million square root checks, which the kernel could theoretically decide through bounded quantifier elimination over finite sets—but the recursion overhead for each iteration makes this computationally expensive, potentially taking hours or days to complete. | | | | I could try encoding this as a single Nat computation with optimized recursion and literal arithmetic to leverage kernel GMP operations, though even that approach is borderline for 5-10 million iterations. Before committing to a kernel proof, I should first check whether a counterexample even exists in a reasonable range—maybe up to 10^12 or 10^13 in special cases—by understanding the structure of low-count solutions. | | | | Now I'm examining how n with count ≤ 2 behaves modulo various small numbers like 5, 7, 8, 9, 11, 13, 16, 25, 32, and 64 to see if there are patterns that constrain where counterexamples could hide. | | I've found that representation counts don't grow uniformly—there are values near 4×10^8 with only one representation, and low-count cases aren't decaying per decade, suggesting arithmetic obstructions in special residue classes. I'll now analyze the structure of these low-count values to see if a counterexample is within reach. | | bash | | | | cd /tmp && python3 << 'EOF' | | low = 1,4655,9590,24935,33845,192080,2155514,2962628,8282657,23343989,39866594,48876188,54847142,72755879,142817024,152956472,392829611,394239767,454535519,498055754,586266734,604180652,674771018,794743079,887859740,936374822 | | for m in 2,3,4,5,7,8,9,11,13,16,25,27,32,49,64,81,121,128 : | | print m, n % m for n in low | | EOF | | | | | | 10 --- TOOL bash --- | | 2 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0 | | 3 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 | | 4 1, 3, 2, 3, 1, 0, 2, 0, 1, 1, 2, 0, 2, 3, 0, 0, 3, 3, 3, 2, 2, 0, 2, 3, 0, 2 | | 5 1, 0, 0, 0, 0, 0, 4, 3, 2, 4, 4, 3, 2, 4, 4, 2, 1, 2, 4, 4, 4, 2, 3, 4, 0, 2 | | 7 1, 0, 0, 1, 0, 0, 4, 4, 5, 4, 5, 4, 0, 0, 0, 4, 6, 5, 4, 0, 4, 5, 5, 4, 5, 5 | | 8 1, 7, 6, 7, 5, 0, 2, 4, 1, 5, 2, 4, 6, 7, 0, 0, 3, 7, 7, 2, 6, 4, 2, 7, 4, 6 | | 9 1, 2, 5, 5, 5, 2, 5, 8, 2, 5, 5, 5, 8, 5, 2, 5, 5, 5, 5, 2, 2, 5, 5, 5, 2, 8 | | 11 1, 2, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 | | 13 1, 1, 9, 1, 6, 5, 10, 6, 6, 6, 1, 10, 12, 1, 12, 6, 5, 12, 9, 1, 1, 10, 12, 0, 1, 6 | | 16 1, 15, 6, 7, 5, 0, 10, 4, 1, 5, 2, 12, 6, 7, 0, 8, 11, 7, 15, 10, 14, 12, 10, 7, 12, 6 | | 25 1, 5, 15, 10, 20, 5, 14, 3, 7, 14, 19, 13, 17, 4, 24, 22, 11, 17, 19, 4, 9, 2, 18, 4, 15, 22 | | 27 1, 11, 5, 14, 14, 2, 23, 26, 2, 5, 14, 5, 17, 5, 11, 14, 23, 23, 23, 11, 20, 5, 5, 23, 2, 26 | | 32 1, 15, 22, 7, 21, 16, 26, 4, 1, 21, 2, 28, 6, 7, 0, 24, 11, 23, 31, 10, 14, 12, 10, 7, 28, 6 | | 49 1, 0, 35, 43, 35, 0, 4, 39, 40, 46, 47, 11, 21, 42, 7, 32, 41, 26, 4, 7, 11, 19, 5, 25, 26, 12 | | 64 1, 47, 54, 39, 53, 16, 58, 4, 33, 53, 34, 28, 38, 39, 0, 56, 43, 23, 31, 10, 46, 44, 10, 39, 28, 38 | | 81 1, 38, 32, 68, 68, 29, 23, 53, 2, 32, 14, 59, 17, 59, 11, 41, 23, 50, 50, 38, 74, 32, 32, 77, 29, 80 | | 121 1, 57, 31, 9, 86, 53, 20, 64, 86, 64, 119, 53, 20, 31, 119, 9, 86, 108, 108, 31, 75, 64, 119, 75, 97, 108 | | 128 1, 47, 118, 103, 53, 80, 122, 68, 33, 117, 98, 28, 38, 39, 0, 56, 43, 23, 95, 74, 110, 44, 74, 39, 28, 38 | | | | | | 11 --- ASSISTANT --- | | I'm noticing a pattern in the triangular numbers modulo 3 and 11—the low-count values seem to cluster around specific residues. Let me trace through how triangular numbers behave under these moduli to understand why certain values appear more frequently. | | | | For modulo 3, triangular numbers only hit residues 0 and 1, never 2. For binomial coefficients C x,4 , I can apply Lucas' theorem with base-3 representation: since 4 = 11 ₃, the value depends only on the last two base-3 digits of x, giving C x,4 ≡ x₁·x₀ mod 3. Similarly for modulo 11, triangular numbers are constrained to a specific set of residues—since 8T+1 must be a quadratic residue, I can work backwards from the squares modulo 11 to find which values T can actually take, giving me exactly 6 possible residues out of 11. | | | | Now when n ≡ 9 mod 11, I need the sum s = C x,4 + C y,6 + C z,8 to land in a complementary set of residues so that n - s hits the allowed triangular residues. This still leaves 6 classes out of 11, so there's no complete obstruction, but the actual density of achievable sums might be much lower. The same constraint applies modulo 3 where n ≡ 2 requires s to be 1 or 2 mod 3. | | | | The key insight is that each binomial coefficient term tends to be 0 mod 3 by Lucas's theorem, which drastically reduces how often the sum avoids 0. This suggests the expected count in the worst residue classes could follow a singular series pattern with a very small constant factor, or might even decay for higher prime powers due to the digit-based structure of Lucas's theorem creating a fractal-like constraint. | | | | To hunt for a counterexample, I should focus on constructing n in residue classes mod 3^k and 11^j that minimize the number of valid x,y,z,T tuples, then search those specific n for zero representations. The mod 3 structure is particularly important since it has the strongest effect, so I need to carefully analyze how many x ≤ X satisfy C x,4 ≡ r mod 3^k using generalized Lucas and Kummer theory, and do the same for triangular numbers. | | | | Looking at the empirical data, certain residues mod 27 consistently show up as hardest—specifically {2,5,11,14,17,20,23,26}, all ≡ 2 mod 3. The pattern holds mod 9 with {2,5,8}, and mod 11 is dominated by residue 9, with mod 121 showing all hard residues ≡ 9 mod 11. | | | | The key insight is that the difficult cases cluster around n ≡ 2 mod 3 and n ≡ 9 mod 11 simultaneously i.e., n ≡ 20 mod 33 . I should test this hypothesis empirically by comparing representation counts for this restricted class against the global distribution at large heights, then use that to estimate the probability of zero representations at even larger N. Since T k mod 33 is periodic with period 33 in k, I only need to check k values in specific residue classes mod 33 for each s, which dramatically reduces the marking work. With this optimization cutting the sieve cost by roughly a factor of 33, I could potentially reach N around 3×10^11 to 10^12 within a few hours, assuming the frequency of zero-count candidates holds up as observed in the smaller data. | | | | The key question is whether the average count in the worst residue class grows or shrinks with n—that determines whether counterexamples are likely infinite and discoverable, or whether they might not exist at all. I need to estimate this empirically by examining how counts behave across different ranges. | | | | If the average grows slowly like a polylogarithmic factor , the distribution might still have heavy tails due to deeper arithmetic structure, creating multiplicative fluctuations similar to a random cascade. In that regime, counts could still hit zero for exceptional values of n even when the overall trend is upward. Rather than speculate further, I should run a class-restricted count sieve to gather actual data. | | | | For efficiency, I'll sample windows at different scales—1e9, 1e10, 1e11—rather than scanning the full range. At a window of size 1e8 centered around 1e12, the cost per window is manageable: roughly 5e7 operations per class check, which is trivial. The overhead from the constant term dominates over the scaling term, making this approach entirely feasible. | | | | Now I'm wondering whether sampling at 1e10, 1e11, 1e12, 1e13, 1e14 will reveal if the hard class's minimum counts drop into the 0–2 range frequently at 1e13. If so, a full sieve of that class up to 1e13 would be prohibitively expensive—around 3e13 marks. But I suspect there's deeper structure lurking in the modular constraints mod 9, 27, 121, and smaller primes like 5 and 7 that could isolate much sparser candidate families. Alternatively, there might be an exact congruence obstruction—some modulus where an entire arithmetic progression has cnt n = 0. | | | | But checking this: if the set {T + C4 + C6 + C8 mod m} missed a residue class entirely, that would give an explicit AP of counterexamples and a straightforward Lean proof. However, small members of any such class are already covered, so no full obstruction exists unless the class only misses under size constraints, which doesn't happen. So all classes have positive counts; the real issue is tail fluctuations approaching zero. | | | | Let me quantify the mod-3 structure: I'm modeling count n as a sum over elements in S3 up to n, checking which differences land in the triangular numbers, and heuristically scaling this with local density factors for each prime. | | | | For p = 3 specifically, the local factor σ 3 n has a complicated multiplicative structure tied to the 3-adic digit representation of n, since C4 mod 3^k exhibits Lucas-like digit patterns. These cascading digit effects could create n values where σ 3 n becomes vanishingly small—potentially decaying faster than n^{1/24} grows—which would generate infinitely many counterexamples constructible by choosing unfavorable digit patterns in base 3. | | | | The key is determining which base-3 digit patterns of n minimize the count of valid t, c4, c6, c8 tuples modulo powers of 3. | | | | Now I'm computing the distribution of T, C4, C6, C8 modulo 3^k for k up to 8, then using the Chinese Remainder Theorem with moduli like 11, 121, and other small primes to construct candidates with minimal representation counts. For each candidate, I can directly count representations by enumerating triples and checking triangular number conditions—the enumeration space scales roughly as the product of fourth, sixth, and eighth roots of n, which at n ≈ 10^14 gives a manageable search space of around a billion triples. | | | | The key optimization is using modular filters: instead of checking every triple, I precompute which residue classes modulo M = 27·11 = 297 are admissible based on the sum s, then iterate only over x values that satisfy the congruence constraints. This residue-class pruning should reduce the effective search space by a factor of 10–30×, making it feasible to test multiple hard candidates. | | | | For a single candidate n at height 10^14, the cost is roughly 3×10^8 isqrt operations after pruning, which takes a few seconds in C. Testing 10^4 candidates across 16 cores would take minutes to an hour—plausible. The next step is to understand the local density functions σ p n for small primes like 3 and 11, then use those to choose residues that minimize the expected count of valid triples, and finally estimate the minimal achievable count at different heights to pick the most promising search region. | | | | Once I find a candidate n₀ where the count drops to zero, I'll need to verify it exhaustively, then prove it in Lean by showing A306477 n₀ = 0—which requires a clever argument since directly evaluating the sum over n₀+1 ^4 terms is infeasible. After the cutoff, there are roughly a hundred million triples to check, which is computationally intensive for Lean's kernel. Each triple requires verifying that 8 n₀−s +1 isn't a perfect square using an integer square root bound. The kernel's decidability checker would need to unfold recursive definitions repeatedly across millions of iterations, making this approach infeasible — even with optimized tail-recursive Nat operations, the overhead per iteration would likely exceed what's practical for kernel reduction. | | | | A better strategy might be finding a counterexample at a lower height where the number of candidate triples drops to around 5-10 million, which would be within the kernel's computational reach. | | I've found a clear pattern: all low-count values with n 1 are congruent to 2 mod 3, and most are congruent to 9 mod 11, suggesting digit-based local obstructions at p=3,11 that create a heavy lower tail. I'll now check the 10^10 run and quantify the local densities modulo powers of 3 and 11. | | bash | | | | cd /tmp && cat sieve10.err sieve10.out 2 /dev/null; ls -la sieve10 | | | | bash | | | | cd /tmp && python3 << 'EOF' | | from math import comb | | distributions mod 3^k and 11^k of each term, using natural density over parameter ranges | | def dist vals, m : | | from collections import Counter | | c = Counter v % m for v in vals | | tot = len vals | | return {r: c r /tot for r in sorted c } | | | | period of C x,4 mod 3^k in x: should be 3^ k+something . Use large sample. | | import itertools | | M3 = 3 4 81 | | sampleN = 3 9 | | c4 = comb x,4 for x in range sampleN | | c6 = comb y,6 for y in range sampleN | | c8 = comb z,8 for z in range sampleN | | tri = k k+1 //2 for k in range 1,sampleN | | for m in 3,9,27 : | | d4=dist c4,m ; d6=dist c6,m ; d8=dist c8,m ; dt=dist tri,m | | convolution: for each n mod m, sum over t,r4,r6,r8 with t+r4+r6+r8=n of product of densities | | conv = 0.0 m | | for rt,pt in dt.items : | | for r4,p4 in d4.items : | | for r6,p6 in d6.items : | | for r8,p8 in d8.items : | | conv rt+r4+r6+r8 %m += pt p4 p6 p8 | | worst = sorted range m , key=lambda n: conv n :6 | | print m, "worst classes:", n, round conv n m,4 for n in worst | | EOF | | | | | | 11 --- TOOL bash --- | | n4=699 n6=137 n8=64 | | |S3|=5426468 with dups 5441000 | | -rw-r--r--. 1 root root 53 Aug 2 19:10 sieve10.err | | -rw-r--r--. 1 root root 0 Aug 2 19:10 sieve10.out | | | | | | 11 --- TOOL bash --- | | 3 worst classes: 2, 0.8148 , 0, 1.0741 , 1, 1.1111 | | 9 worst classes: 5, 0.7654 , 2, 0.8395 , 8, 0.8395 , 6, 1.0658 , 0, 1.0782 , 3, 1.0782 | | 27 worst classes: 23, 0.7654 , 5, 0.7654 , 14, 0.7654 , 17, 0.8395 , 26, 0.8395 , 2, 0.8395 | | | | | | 12 --- ASSISTANT --- | | Looking at the mod-3^k factors and how they behave — the worst case stabilizes around 0.7654 for n≡5 mod 9, which doesn't cascade toward zero but rather plateaus. The issue is that I'm treating the parameter density uniformly, but there's a subtlety with the local densities at p=3 that affects how the counting measure distributes across residue classes modulo powers of 3. | | | | The periodicity of C x,4 mod 3^k in x means sampling over a full period should capture the behavior accurately. But the 0.7654 factor alone doesn't explain the heavy tail I'm observing — the real pattern emerges when I look at the combined constraints: almost all low-count cases satisfy n≡2 mod 3 AND n≡9 mod 11 simultaneously, which suggests the variance-driving structure comes from interactions across multiple primes rather than from any single modulus. I should compute the convolution factors for mod 11, 121, 5, 7, and other small primes to see where the substantial combined reduction actually comes from. | | The 10^10 sieve is still running with a mild mod-3 factor of 0.77×. I'll compute local factors for more primes to understand what makes those n values difficult. | | bash | | | | cd /tmp && python3 << 'EOF' | | from math import comb | | from collections import Counter | | def dist vals, m : | | c = Counter v % m for v in vals ; tot=len vals | | return {r: c r /tot for r in c} | | def conv factors m, P : | | c4= comb x,4 for x in range P | | c6= comb y,6 for y in range P | | c8= comb z,8 for z in range P | | tri= k k+1 //2 for k in range 1,P+1 | | d4=dist c4,m ; d6=dist c6,m ; d8=dist c8,m ; dt=dist tri,m | | conv= 0.0 m | | for rt,pt in dt.items : | | for r4,p4 in d4.items : | | s1= rt+r4 %m; p1=pt p4 | | for r6,p6 in d6.items : | | s2= s1+r6 %m; p2=p1 p6 | | for r8,p8 in d8.items : | | conv s2+r8 %m +=p2 p8 | | return conv | | import sys | | for m,P in 11,11 3 8 , 121,11 3 8 , 5,5 4 , 25,5 5 , 7,7 4 , 49,7 4 , 8,2 10 , 16,2 11 , 32,2 12 , 13,13 3 , 2,2 8 : | | conv=conv factors m,P | | worst=sorted range m , key=lambda n: conv n :8 | | print m, n, round conv n m,4 for n in worst | | EOF | | | | | | 12 --- TOOL bash --- | | 11 9, 0.595 , 8, 0.8595 , 10, 0.9174 , 2, 0.9256 , 3, 0.9587 , 7, 0.9752 , 5, 1.0248 , 6, 1.1074 | | 121 9, 0.595 , 31, 0.595 , 64, 0.595 , 119, 0.595 , 20, 0.595 , 53, 0.595 , 86, 0.595 , 42, 0.595 | | 5 4, 0.904 , 2, 0.928 , 3, 0.976 , 0, 1.072 , 1, 1.12 | | 25 19, 0.8896 , 24, 0.9056 , 14, 0.9056 , 9, 0.9056 , 4, 0.9136 , 2, 0.928 , 17, 0.928 , 22, 0.928 | | 7 5, 0.9067 , 6, 0.9679 , 2, 0.9679 , 4, 0.9679 , 3, 1.0087 , 0, 1.0496 , 1, 1.1312 | | 49 19, 0.9038 , 33, 0.9038 , 40, 0.9038 , 47, 0.9067 , 26, 0.9096 , 5, 0.9096 , 12, 0.9096 , 27, 0.9679 | | 8 0, 1.0 , 1, 1.0 , 2, 1.0 , 3, 1.0 , 4, 1.0 , 5, 1.0 , 6, 1.0 , 7, 1.0 | | 16 0, 1.0 , 1, 1.0 , 2, 1.0 , 3, 1.0 , 4, 1.0 , 5, 1.0 , 6, 1.0 , 7, 1.0 | | 32 0, 1.0 , 1, 1.0 , 2, 1.0 , 3, 1.0 , 4, 1.0 , 5, 1.0 , 6, 1.0 , 7, 1.0 | | 13 1, 0.8876 , 5, 0.9112 , 7, 0.9112 , 12, 0.9172 , 0, 0.9349 , 10, 0.9586 , 9, 0.9586 , 11, 0.9941 | | 2 0, 1.0 , 1, 1.0 | | | | | | 13 --- ASSISTANT --- | | The worst modular factors give a combined reduction of only about 3×, which doesn't account for the extremely low counts I'm seeing at certain values of n. I need to reconsider the actual structure: the count at each n depends on how many triples x,y,z sum to some s ≤ n such that n−s is triangular, which is a much sparser condition than the modular constraints alone suggest. Let me compute the expected count more carefully using the density of triangular numbers and the distribution of triple sums. I need to check the mod 81, 243, and higher powers of 11 for the worst-case classes to see if the factors keep decreasing multiplicatively with each digit level — if so, the minimum λ n could decay faster than polynomial, potentially like N^{1/24 - c} where c depends on how quickly the digit-dependent factors cascade down. | | | | Now I'm computing the periods of binomial coefficient polynomials modulo powers of 3 and 5 to determine their exact distributions on the digit-restricted subtrees — C x,4 depends on x mod 3^{k+1}, C y,6 on y mod 3^{k+2}, and C z,8 on z mod 3^{k+3} due to the factorial denominators. | | The small-modulus factors I found can't account for the observed counts near 10^9, so there's likely a deeper digit cascade at play. I'll now compute worst-class factors modulo powers of 3 and 11 recursively to check if the worst factor keeps shrinking with depth. | | bash | | | | cd /tmp && python3 << 'EOF' | | from math import comb | | from collections import Counter | | | | def factors pk p, kmax, extra=2 : | | res = | | for k in range 1, kmax+1 : | | m = p k | | P = p k+extra | | d4 = Counter comb x,4 %m for x in range P | | d6 = Counter comb y,6 %m for y in range P | | d8 = Counter comb z,8 %m for z in range P | | dt = Counter x x+1 //2 %m for x in range 1,P+1 | | tot4=tot6=tot8=tott=P | | conv= 0.0 m | | for rt,pt in dt.items : | | for r4,p4 in d4.items : | | s1= rt+r4 %m; q1=pt p4 | | for r6,p6 in d6.items : | | s2= s1+r6 %m; q2=q1 p6 | | for r8,p8 in d8.items : | | conv s2+r8 %m +=q2 p8 | | conv= c/ P 4 m for c in conv | | worst=sorted range m , key=lambda n: conv n :5 | | res.append m, n, round conv n ,5 for n in worst | | return res | | | | for m,w in factors pk 3,7 : | | print m,w | | EOF | | | | | | 13 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 14 --- ASSISTANT --- | | The naive O m^4 approach is too slow for m=2187, so I'll use FFT-based circular convolution instead—treating the probability distributions as arrays and using numpy's FFT to compute the convolution efficiently in frequency space, then transforming back. | | bash | | | | cd /tmp && python3 << 'EOF' | | import numpy as np | | from math import comb | | def darr vals, m : | | a=np.zeros m | | for v in vals: a v%m +=1 | | return a/len vals | | def cconv a,b : | | m=len a | | return np.real np.fft.ifft np.fft.fft a np.fft.fft b | | def worst p,kmax,extra=3,top=6 : | | for k in range 1,kmax+1 : | | m=p k; P=p k+extra | | d4=darr comb x,4 for x in range P ,m | | d6=darr comb y,6 for y in range P ,m | | d8=darr comb z,8 for z in range P ,m | | dt=darr x x+1 //2 for x in range 1,P+1 ,m | | conv=cconv cconv d4,d6 ,cconv d8,dt m | | idx=np.argsort conv :top | | print m, int i ,round float conv i ,5 for i in idx | | worst 3,8 | | print | | worst 11,4,extra=1 | | print | | worst 2,10,extra=4 | | EOF | | | | | | 14 --- TOOL bash --- | | 3 2, 0.81481 , 0, 1.07407 , 1, 1.11111 | | 9 5, 0.76543 , 2, 0.83951 , 8, 0.83951 , 6, 1.06584 , 0, 1.07819 , 3, 1.07819 | | 27 14, 0.76543 , 23, 0.76543 , 5, 0.76543 , 26, 0.83951 , 11, 0.83951 , 20, 0.83951 | | 81 14, 0.76543 , 50, 0.76543 , 77, 0.76543 , 5, 0.76543 , 32, 0.76543 , 23, 0.76543 | | 243 77, 0.76543 , 212, 0.76543 , 41, 0.76543 , 59, 0.76543 , 221, 0.76543 , 68, 0.76543 | | 729 68, 0.76543 , 257, 0.76543 , 86, 0.76543 , 680, 0.76543 , 581, 0.76543 , 266, 0.76543 | | 2187 1796, 0.76543 , 1733, 0.76543 , 815, 0.76543 , 824, 0.76543 , 1724, 0.76543 , 239, 0.76543 | | 6561 4217, 0.76543 , 860, 0.76543 , 2840, 0.76543 , 4982, 0.76543 , 6080, 0.76543 , 2831, 0.76543 | | | | 11 9, 0.59504 , 8, 0.8595 , 10, 0.91736 , 2, 0.92562 , 3, 0.95868 , 7, 0.97521 | | 121 31, 0.59504 , 86, 0.59504 , 20, 0.59504 , 53, 0.59504 , 108, 0.59504 , 97, 0.59504 | | 1331 592, 0.59504 , 97, 0.59504 , 966, 0.59504 , 1120, 0.59504 , 152, 0.59504 , 185, 0.59504 | | 14641 9997, 0.59504 , 1230, 0.59504 , 9348, 0.59504 , 10514, 0.59504 , 5773, 0.59504 , 7412, 0.59504 | | | | 2 0, 1.0 , 1, 1.0 | | 4 0, 1.0 , 1, 1.0 , 2, 1.0 , 3, 1.0 | | 8 0, 1.0 , 1, 1.0 , 2, 1.0 , 3, 1.0 , 4, 1.0 , 5, 1.0 | | 16 0, 1.0 , 1, 1.0 , 2, 1.0 , 3, 1.0 , 4, 1.0 , 5, 1.0 | | 32 0, 1.0 , 29, 1.0 , 28, 1.0 , 27, 1.0 , 26, 1.0 , 25, 1.0 | | 64 0, 1.0 , 34, 1.0 , 35, 1.0 , 36, 1.0 , 37, 1.0 , 38, 1.0 | | 128 0, 1.0 , 93, 1.0 , 92, 1.0 , 91, 1.0 , 90, 1.0 , 89, 1.0 | | 256 0, 1.0 , 162, 1.0 , 163, 1.0 , 164, 1.0 , 165, 1.0 , 166, 1.0 | | 512 0, 1.0 , 349, 1.0 , 348, 1.0 , 347, 1.0 , 346, 1.0 , 345, 1.0 | | 1024 0, 1.0 , 674, 1.0 , 675, 1.0 , 676, 1.0 , 677, 1.0 , 678, 1.0 | | | | | | 15 --- ASSISTANT --- | | I'm working through the local stability conditions and finding that the worst-case combined product of singular factors comes to roughly 0.33, which scales the global mean. Now I need to compute the global mean λ̄ n numerically at 10^9 by summing over all triples up to that point, then multiply by the worst-class factor to get the expected bound. Looking at the actual empirical counts from the data up to 1e9, I see cnt=1 appears about 5 times, cnt=2 around 21 times, and cnt≤3 totals roughly 121 values. The distribution looks fairly flat across decades, so if I assume a geometric-like ratio between consecutive counts—roughly 0.2 based on the 1s-to-2s ratio—I can extrapolate backward to estimate how many zeros might exist per decade. | | | | This suggests a counterexample could plausibly appear in the 1e10–1e12 range, even though none have shown up through 1e9. I'm noticing that all the large counterexamples with cnt≤2 seem to cluster in specific residue classes: they're all ≡ 2 mod 3 and mostly ≡ 9 mod 11, which points to n ≡ 20 mod 33 as a promising restricted search space. Let me verify this pattern holds for the biggest values and narrow down where to hunt next. Now I'm estimating the computational cost: with the restricted residue class mod 33, the total marks drop to around 1.5e12 across 16 cores, which would be roughly 1e11 per core or 5-10 minutes per 1e11 operations. But that estimate feels optimistic, so I'm recalculating the actual mark count M N by summing over all elements in S3 N weighted by sqrt 2 N−s . From earlier measurements at 1e9, the coverage sieve ran in about 34 seconds on a single core 3 minutes across 16 cores , with roughly 1.5e6 elements in S3 and an average sqrt term around 0.75·sqrt 2e9 . | | | | That gives about 5e10 total marks in 180 cpu-seconds, or roughly 3.6e8 marks per cpu-second. Scaling this up: at 1e10 I'd expect around 5.4e11 marks taking about 1500 cpu-seconds roughly 3 minutes wall time , at 1e11 around 6e12 marks in 4.5 hours cpu 20 minutes wall , and at 1e12 around 7e13 marks in 50 hours cpu about 3.2 hours wall on 16 cores . With the class restriction factored in, 1e12 should complete in roughly 6 minutes wall time. | | | | For larger scales, 1e13 would generate around 1.6e13 marks taking about 30 minutes wall time, while 1e14 would produce 1.76e14 marks in roughly 5.5 hours wall. Memory-wise, the bitset per block approach works fine, but at 1e14 the S3 array alone would need about 24 GB 3e9 entries at 8 bytes each , which is manageable within the 123 GB available. The main concern is the per-block overhead when dealing with hundreds of thousands of blocks at that scale. | | | | The issue is that iterating through all s-values for each block creates 2e15 pair-visits, which is prohibitively slow. Even reversing the iteration order s outer, blocks inner doesn't help since I'd need a full-range bitset covering 1e14 bits—that's 12.5 TB. A class-compressed bitset storing only residues ≡ 20 mod 33 would reduce this to 375 GB, still infeasible. So this bitset method hits a wall around 3e12. For larger heights, I'd need to switch to candidate filtering with multi-modulus scoring, computing λ n through local factors at several primes, though the factors stabilize quickly so λ n essentially depends only on n itself. The Poisson model seems to underestimate the probability of zeros because the actual distribution is overdispersed—empirical data shows far fewer count≤2 cases than predicted, suggesting the tail behavior is different. Given that count=1 appears around 4e8, extrapolating downward hints there might be a zero somewhere in the 1e10–1e13 range, though it's hard to pin down without more computation. I should also consider whether restricting the search space further could help. | | | | Looking at the modular constraints, if I focus on n ≡ 5 mod 9 and n ≡ 9 mod 11 which gives n ≡ 86 mod 99 , I can reduce the search space by a factor of about 0.765·0.595. The mod 9 residue 5 dominates the low-count cases at roughly 60%, so restricting to this mod 99 class would let me search up to 1e13 within reasonable computational bounds—around an hour of wall time and about 12.5 GB of memory for a bitset covering the full range. | | | | For the actual implementation, I'm considering a segmented sieve approach where I iterate over blocks of the n-range with the S3 values sorted, using class-compressed bitsets to store only the relevant residues. With |S3| around 2.4e8 and blocks of roughly 3.3e9 values each, I'd have about 3000 blocks total, giving an overhead of around 7e11 operations—manageable within the constraints. | | | | But the visits are too slow with that granularity. I need much larger blocks—around 2^31 bits covering roughly 2.1e11 of the n-range for class 99—which brings the block count down to just 47 and the overhead to about 1e10. The random writes within each block are cache-hostile at that scale, but still hitting RAM speeds of maybe 5-10 nanoseconds per mark. With roughly 6e12 total marks to process across all s values, that's around 42,000 seconds of work, which parallelizes to about 44 minutes across 16 cores. | | | | Scaling to 1e14 pushes the mark count to 6.7e13, which would take about 8 hours wall-clock time, and the S3 data structure balloons to 6.7GB, but that's manageable as a shared resource. The block count jumps to 470, and the overhead from visits becomes more noticeable—maybe 1-2 hours extra—but it's still feasible. | | | | So the plan is to start with a full sieve up to 1e10 as a sanity check and potential source of counterexamples, then move to the next stage. I could also expand the search to combined modular restrictions using mod 5, 7, and 13 alongside mod 9 and 11, which would let me reach up to 3e14 or even 1e15 without much additional cost. The trade-off is that the counterexample might fall outside these restricted classes, but the Poisson analysis suggests that restricting to smaller classes with lower expected counts actually increases the probability of finding a zero, so it's worth being aggressive with the modular constraints. | | | | My strategy: score each residue class mod 45045 by its product factor, then sieve through the top 100 classes with the smallest factors. I should also verify that the local factor for prime 2 is indeed 1.0 which checks out , and scan through all primes up to around 61 to see if any have unexpectedly strong factors that would be worth including in the restrictions. | | | | Before diving into the class sieve, I need to validate the model by comparing empirical counts against the predicted λ values for known low-count cases, then check the status of the 1e10 job and build out the prime factors table. | | I've confirmed there's no cascade effect and local factors are stabilizing the lower tail, which appears to be fluctuation-driven with counts persisting to 10^9. Next I'll check the 10^10 run, scan other primes for factors, and build a class-restricted deep sieve. | | bash | | | | cd /tmp && cat sieve10.err sieve10.out | | | | bash | | | | cd /tmp && python3 << 'EOF' | | import numpy as np | | from math import comb | | import sympy | | def darr vals,m : | | a=np.zeros m | | for v in vals: a v%m +=1 | | return a/len vals | | def cconv a,b : | | return np.real np.fft.ifft np.fft.fft a np.fft.fft b | | res={} | | for p in sympy.primerange 2,80 : | | m=p; P=p p p if p<20 else 1 | | P=max P, 4096 | | d4=darr comb x,4 for x in range P 1 ,m | | d6=darr comb y,6 for y in range P ,m | | d8=darr comb z,8 for z in range P ,m | | dt=darr x x+1 //2 for x in range 1,P+1 ,m | | conv=cconv cconv d4,d6 ,cconv d8,dt m | | i=int np.argmin conv | | res p = i, float conv i | | print p, i, round float conv i ,4 | | EOF | | | | | | 15 --- TOOL bash --- | | n4=699 n6=137 n8=64 | | |S3|=5426468 with dups 5441000 | | done N=10000000000 bad=0 | | | | | | 15 --- TOOL bash --- | | 2 0 1.0 | | 3 2 0.8147 | | 5 4 0.9037 | | 7 5 0.9061 | | 11 9 0.5944 | | 13 1 0.8877 | | 17 14 0.8304 | | 19 14 0.8753 | | 23 19 0.8921 | | 29 11 0.9582 | | 31 24 0.9635 | | 37 9 0.9803 | | 41 34 0.9673 | | 43 11 0.9657 | | 47 39 0.972 | | 53 44 0.9736 | | 59 56 0.987 | | 61 0 0.9818 | | 67 61 0.9913 | | 71 18 0.9887 | | 73 20 0.9886 | | 79 76 0.9896 | | | | | | 16 --- ASSISTANT --- | | I've verified the conjecture holds up to 10^10 with no counterexamples found, and the OEIS data confirms this. For larger primes like p ≥ 23, my sampling period might not perfectly capture the exact distribution since I'm using P ≥ 4096 rather than accounting for all multiples of p², but these minor inaccuracies shouldn't affect the overall findings. The density factors are varying interestingly across different primes—p=11 gives 0.594, p=3 shows 0.765 consistent when checking mod 9 , p=17 reaches 0.83, p=13 is at 0.888, while p=19 appears to be 0. | | | | 875 and p=23 is around 0.89, with p=5 and p=7 both near 0.90. Multiplying these worst-case factors together across all primes up to 23 gives roughly 0.21, suggesting the hardest cases fall about 5 times below the global average. To calibrate this properly, I need to compute what the actual global mean count looks like at 10^9 and then examine specific difficult values of n with local corrections, which should reveal whether λ min n follows the predicted n^{1/24} scaling—the observed count of 1 at 3.9×10^8 seems roughly consistent with this model. | | | | Scaling from 10^9 up to 10^13 multiplies λ min by about 1.47, pushing it to roughly 12.5, which gives an exponential suppression factor of 3.7×10^-6. The deepest equivalence class modulo the product of all these primes contains only about 30,000 members up to 10^13, so with that exponential penalty the expected count drops below 0.1. | | | | This suggests I need to balance the restriction level more carefully—trading off class size against the decay rate λ. Using a Poisson model, the expected number of zeros in a class is proportional to N/|M| ·exp −λ , so the exponential term dominates. I should include a prime p in the restriction only if the reduction in λ outweighs the cost of shrinking the modulus, roughly when λ times the fractional gain exceeds log p . Starting from an unrestricted global λ around 66 at 10^13, I can iteratively decide which primes to include based on this trade-off. So I'm restricting to the modulus formed by those selected primes—about 2.1 million—and computing the density parameter λ as roughly 17.5, which gives an exponential decay of 2.5×10⁻⁸. That means up to 10¹³, I'd expect around 4.8 million members satisfying these conditions. | | | | The Poisson model with λ around 45 at 10⁹ predicts almost no zeros, but I'm seeing empirical evidence of at least one zero near 3.9×10⁸, which suggests the actual distribution has a much heavier tail than the model accounts for. I think I'm conflating different λ values for different ranges—I need to step back and directly measure the mean count from the empirical data at 10⁹ to get a clearer picture of what's actually happening. | | | | Rather than keep guessing, I should modify the sieve to output a histogram of counts for specific residue classes like n ≡ 86 mod 99 across multiple sample windows at heights 10⁹ through 10¹³, each spanning 10⁸ integers. This data-driven approach will let me see the actual distribution shape and extrapolate properly. Optimizing the window sieve by filtering which k values to check: instead of testing every mark's residue modulo 33, I can precompute which residue classes of T k will satisfy the constraint for each s, then only iterate through those k values—this reduces the mark visits from ~5e9 per window down to roughly a fifth of that, though there's some per-s overhead in computing the valid k ranges. Estimating the total marks across a residue class up to 10^13 by factoring in the average divisor count and class-specific density adjustments — roughly 3×10^11 marks with a per-mark cost of ~7ns, which scales to about 68000 seconds, or roughly 1.2 hours after parallelizing across 16 cores. | | | | Now I'm planning to write a sampling utility that takes a window size and starting point, computing divisor counts for numbers in the residue class 20 mod 33 within that range, then breaking down the results further by additional modular constraints to build histograms of the count distributions across various subclasses. | | | | The approach is to dump raw count data to a file indexed by position within the residue class, letting Python handle the flexible analysis afterward. With a window of 100 million elements, I'd get around 3 million entries in the target class—enough to capture the tail behavior down to probabilities around 1e-5. Testing across different starting points from 1 billion up to 4 trillion should take roughly 30 seconds per window at the largest scale, which is manageable. For the full S3 generation up to 1e13, I'm looking at about 240 million elements totaling 2GB, and the triple-loop generation plus sorting should complete without issues. | | | | Rather than regenerating S3 from scratch for each window run, I'll consolidate everything into a single C program that takes a list of window starting positions, generates S3 once up to the maximum needed value, then iterates through each window using that precomputed data. | | I've verified no counterexamples up to 10^10 and identified several primes with significant worst-class factors. Now I'll build a window sampler to get exact count distributions in the hard classes across heights from 10^9 to 10^13, which will help determine the search strategy. | | bash | | | | cat /tmp/window.c << 'EOF' | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <string.h | | include <math.h | | include <omp.h | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | typedef int64 t i64; | | u64 isqrt64 u64 x { u64 r= u64 sqrtl long double x ; while r 0&&r r x r--; while r+1 r+1 <=x r++; return r;} | | int cmp64 const void a, const void b { u64 x= const u64 a, y= const u64 b; return x<y?-1: x y?1:0 ;} | | | | int main int argc,char argv { | | // usage: window NSTART W - counts for n in NSTART, NSTART+W with n%33==20 | | u64 N0=strtoull argv 1 ,0,10 , W=strtoull argv 2 ,0,10 ; | | u64 NMAX=N0+W; | | // generate S3 with multiplicity <= NMAX | | u64 c4=0, c6=0, c8=0; long n4=0,n6=0,n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; n4++;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; n6++;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; n8++;} | | c4=malloc 8 n4 ; c6=malloc 8 n6 ; c8=malloc 8 n8 ; | | n4=n6=n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; c4 n4++ = u64 v;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; c6 n6++ = u64 v;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; c8 n8++ = u64 v;} | | fprintf stderr,"n4=%ld n6=%ld n8=%ld\n",n4,n6,n8 ; | | // count S3 size | | long cap=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { if c4 i +c6 j +c8 k NMAX break; cap++;}} | | u64 S3=malloc 8 cap ; long nS3=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { u64 s=c4 i +c6 j +c8 k ; if s NMAX break; S3 nS3++ =s;}} | | fprintf stderr,"|S3 with mult|=%ld\n",nS3 ; | | // residue lookup: for target residue r mod 33, ks r = list of k mod 33 with k k+1 /2 % 33 == r | | int ks 33 33 , nks 33 ; | | memset nks,0,sizeof nks ; | | for int k=0;k<33;k++ { int t= k k+1 /2 %33; ks t nks t ++ =k; } | | // base: smallest n = N0 with n%33==20 | | u64 base=N0 + 20 + 33 - N0%33 %33 ; | | u64 M = NMAX base ? NMAX-1-base /33 + 1 : 0; // number of class members | | uint16 t cnt=calloc M,2 ; | | pragma omp parallel | | { | | int tid=omp get thread num , nt=omp get num threads ; | | for long i=tid;i<nS3;i+=nt { | | u64 s=S3 i ; | | if s =NMAX break; | | int r= int 20 + 33 - int s%33 %33 ; // need T ≡ r mod 33 | | u64 lo = N0 s ? N0-s : 1; // T = lo, T = 1 | | u64 hi = NMAX-1-s; | | for int j=0;j<nks r ;j++ { | | int km=ks r j ; | | // smallest k ≡ km mod 33 with T k = lo and k =1 | | u64 kmin = isqrt64 8 lo+1 -1 /2; if kmin<1 kmin=1; | | while kmin kmin+1 /2 < lo kmin++; | | u64 k = kmin + km + 33 - i64 kmin%33 %33 ; | | if k<1 k+=33; | | u64 t=k k+1 /2; | | while t<=hi { | | u64 n=s+t; | | u64 idx= n-base /33; | | pragma omp atomic | | cnt idx ++; | | t += 33 k + 561; // T {k+33}-T k = 33k + 33 34/2 | | k += 33; | | } | | } | | } | | } | | // output binary counts | | char fname 256 ; sprintf fname,"win %llu %llu.u16", unsigned long long N0, unsigned long long W ; | | FILE f=fopen fname,"wb" ; | | fwrite &base,8,1,f ; fwrite &M,8,1,f ; | | fwrite cnt,2,M,f ; fclose f ; | | // quick stats | | u64 mn=65535; long double sum=0; | | for u64 i=0;i<M;i++ { if cnt i <mn mn=cnt i ; sum+=cnt i ; } | | fprintf stderr,"window %llu..%llu class20mod33: M=%llu min=%llu avg=%.2Lf\n", unsigned long long N0, unsigned long long NMAX, unsigned long long M, unsigned long long mn,sum/M ; | | long hist 16 ; memset hist,0,sizeof hist ; | | for u64 i=0;i<M;i++ if cnt i <16 hist cnt i ++; | | for int c=0;c<16;c++ if hist c fprintf stderr," cnt=%d : %ld\n",c,hist c ; | | return 0; | | } | | EOF | | gcc -O3 -march=native -fopenmp -o /tmp/window /tmp/window.c -lm && echo ok | | | | | | 16 --- TOOL bash --- | | ok | | | | | | 17 --- ASSISTANT --- | | bash | | | | cd /tmp && ./window 900000000 100000000 2 &1 | tail -25 | | | | | | 17 --- TOOL bash --- | | n4=393 n6=93 n8=47 | | |S3 with mult|=1523824 | | window 900000000..1000000000 class20mod33: M=3030303 min=2 avg=28.34 | | cnt=2 : 1 | | cnt=3 : 2 | | cnt=4 : 9 | | cnt=5 : 44 | | cnt=6 : 120 | | cnt=7 : 314 | | cnt=8 : 781 | | cnt=9 : 1564 | | cnt=10 : 3123 | | cnt=11 : 5584 | | cnt=12 : 9560 | | cnt=13 : 14933 | | cnt=14 : 22946 | | cnt=15 : 33307 | | | | | | 18 --- ASSISTANT --- | | Looking at the distribution of counts at 1e9, I'm seeing massive overdispersion compared to what a Poisson distribution would predict—the tail is far heavier than expected, with counts decaying geometrically at a ratio around 2.5-3 rather than following the theoretical model. This suggests the rate parameter λ n itself is varying significantly across the data. | | | | To understand whether zeros are actually reachable, I'm planning to sample the distribution at progressively larger heights—4e9, 1.6e10, 6.4e10, 2.6e11, 1e12, 4e12, 1.6e13—to track how the tail behavior evolves and whether the probability of hitting zero classes increases or decreases with scale. I'm also going to analyze the subclass structure of the low-count members modulo small primes like 9, 17, and 19 to narrow down which classes are most likely to contain zeros. | | I found massive overdispersion at height 10^9 with a class average of 28 but minimum of 2, suggesting a heavy geometric-like tail. Now I'll sample the tail at increasing heights to see how quickly it recedes. | | bash | | | | cd /tmp && for N in 4000000000 16000000000 64000000000; do ./window $N 100000000 2 &1 | grep -E "class20|cnt=" | head -8; done | | | | | | 18 --- TOOL bash --- | | window 4000000000..4100000000 class20mod33: M=3030303 min=3 avg=29.69 | | cnt=3 : 4 | | cnt=4 : 6 | | cnt=5 : 24 | | cnt=6 : 76 | | cnt=7 : 198 | | cnt=8 : 472 | | cnt=9 : 980 | | window 16000000000..16100000000 class20mod33: M=3030303 min=4 avg=31.39 | | cnt=4 : 5 | | cnt=5 : 5 | | cnt=6 : 25 | | cnt=7 : 81 | | cnt=8 : 179 | | cnt=9 : 464 | | cnt=10 : 940 | | window 64000000000..64100000000 class20mod33: M=3030303 min=3 avg=33.30 | | cnt=3 : 1 | | cnt=4 : 1 | | cnt=5 : 3 | | cnt=6 : 11 | | cnt=7 : 29 | | cnt=8 : 90 | | cnt=9 : 214 | | | | | | 19 --- ASSISTANT --- | | Looking at the tail behavior at 6.4e10, the count of 3 appears roughly once per 3 million class members, and extrapolating the pattern suggests the probability distribution follows a geometric-like progression where P 2 is around 1/3 per window, P 1 is 1/9, and P 0 is 1/27 across a 1e8 range. | | | | But this naive extrapolation breaks down when compared to actual sieve results—the full sieve found no zeros up to 1e10, yet the geometric model would predict around 3 zeros in that range. The issue is that the tail isn't purely geometric; the lowest counts are much rarer than the model suggests because they come from small positive values of λ, where the mixed Poisson distribution makes P 0 and P 1 more comparable than expected. With effective λ around 3-5 in the extreme subclass, the ratio P 0 /P 1 is closer to 1/3, which still hints zeros shouldn't be far away—yet they're not appearing. | | | | To get a clearer picture, I'm planning to sample at much larger heights 2.56e11, 1e12, 4e12, 1.6e13 using bigger windows to probe the tail more aggressively, though the computational cost scales roughly linearly with the sieve size and window width. | | | | I'm also going to dig into the residue patterns of the low-count integers from the saved windows, looking at how they distribute modulo small primes like 9, 5, 7, 13, 17, 19, and 23 to see if there's a structural constraint I'm missing. | | The tail is receding slowly with cnt=3 still present at $6.4\times10^{10}$. I'll sample higher and analyze residues of the extreme-tail members for more targeted results. | | bash | | | | cd /tmp && for N in 256000000000 1000000000000; do ./window $N 200000000 2 &1 | grep -E "class20|cnt=" | head -8; done | | | | | | 19 --- TOOL bash --- | | window 256000000000..256200000000 class20mod33: M=6060607 min=3 avg=35.69 | | cnt=3 : 2 | | cnt=5 : 1 | | cnt=6 : 8 | | cnt=7 : 30 | | cnt=8 : 74 | | cnt=9 : 186 | | cnt=10 : 430 | | window 1000000000000..1000200000000 class20mod33: M=6060606 min=4 avg=37.78 | | cnt=4 : 1 | | cnt=6 : 3 | | cnt=7 : 7 | | cnt=8 : 27 | | cnt=9 : 99 | | cnt=10 : 225 | | cnt=11 : 462 | | | | | | 20 --- ASSISTANT --- | | Looking at the density patterns across different scales, the count thins dramatically as we go deeper—at 1e12 there's a minimum of 4 in a 2e8 window, dropping to 3 at 2.56e11. The rate suggests roughly 1 occurrence per 1e8 range at that scale, making the probability of zero essentially negligible from a ratio perspective. But there could be much rarer, deeply nested subclasses lurking in the data—ones with all the worst residue combinations across those moduli—and since the window only contains 6 million class members, these extreme subclasses would be sparse enough to hide. | | | | Now I'm calculating the expected counts for these deepest subclasses by working through the modular factors. The all-worst subclass members appear roughly once per 2.1 million in the modulus, so in a 2e8 window I'd expect around 100 members. Their average counts are substantially lower than the class average—about 44% of the typical value. I'm computing the global average lambda at 1e12 by dividing the baseline 37.78 by the combined class factor of 0.484, which gives roughly 78. For the deepest subclass, I'm multiplying through all the individual prime modular factors—starting with 0.7654 for mod 9, 0.594 for mod 11, then 0.830, 0.875, 0.888, 0.892, 0.904, 0.906 for the remaining primes, and continuing through the larger primes with factors all hovering near 0.96 to 0.99. | | | | This product comes out to about 0.165, so the deep subclass lambda at 1e12 is roughly 78 times 0.165, which is about 12.9. With the mixed-Poisson model and overdispersion factored in, the probability of observing zero counts among deep-class members might be somewhere between 1e-4 and 1e-3. The observed data shows a minimum count of 4 across roughly 6 million class-33 members, and the deep subclass represents only about 1 in 63,000 of those members. | | | | The direct approach would be to sample only from the deep subclass over a much larger range and compute their counts individually. At 1e12, the exact enumeration cost breaks down to checking roughly 3 million candidate triples, which would take about 0.5 to 1 second per value of n — far too slow if I need to handle millions of values. | | | | Instead, I'm using a modular admissibility pruning strategy: precompute which residue classes modulo some composite M like 27·11·5·7·13·16 are admissible, then for each fixed pair y,z , step through x values that satisfy the residue constraints. Since only about 1 in 5 to 1 in 10 triples pass the modular filter, this gives roughly a 10× speedup by skipping most candidates before computing the expensive isqrt check. | | | | The practical cost is around 3×10^7 cheap table lookups plus 3×10^6 actual isqrt operations per n, which runs in 100–150ms per candidate. For 10^5 candidates across 16 cores, that's roughly 15 minutes total. | | | | The real question is which n values to test: I'm focusing on deep-class members in the range 10^10, 10^13 , which have density 1/M where M ≈ 3.3×10^8 after including the modular constraints. | | | | That gives about 30,000 members to test, doable in 1–2 hours. The expected Liouville value at 10^13 is around λ ≈ 14, which predicts maybe 0.3 hits across all samples—pretty sparse. Even restricting to fewer primes M = 2.1×10^6 to get 5×10^6 members and λ ≈ 17 doesn't help much. The key insight is that the actual data shows massive overdispersion: among 3×10^6 class-33 members near 6.4×10^10, the minimum count was 3 while the average was 33, whereas Poisson would predict P count ≤ 3 | λ = 33 ≈ 10^-11. This mixed-Poisson structure is what really matters for the search. | | | | The huge variation in λ across different n is the real puzzle—the low tail is driven by rare n where λ drops to 4–8. The question is what specifically pushes λ down for certain n beyond just their prime factorization. If I can understand or construct n that minimize λ directly, I could potentially find zeros at much larger heights. The variation comes from how each prime p contributes a multiplicative factor to λ n , and the product across all primes creates genuine fluctuation in this quantity. | | | | Looking at the empirical data across primes, the deviations from 1 decay slowly—around 1–4% for primes up to 79—following roughly a p^{-1/2} pattern. The sum of these deviations over all primes diverges, which means the cumulative effect of prime contributions could be substantial. | | | | The key insight is that the infimum of the product of local factors σ p n over all n is actually zero—the local factors can compound across many primes simultaneously. When n is chosen to hit bad residues modulo all primes up to some bound P, the density λ n gets suppressed by roughly exp −c√P/log P . But n itself must be around e^P to satisfy all those residue constraints, so there's a tension: the n^{1/24} growth from the main term eventually dominates the exponential suppression, yet for moderate heights the √P decay can still be the controlling factor. | | | | Now I'm checking concrete numbers: at height around 10^10, the global average λ is roughly 78, and to push the minimum down to ~1 I'd need to suppress by a factor of 64 using carefully chosen bad residues across primes up to around 200. Looking at the per-prime contributions, the worst offenders are 3, 11, 17, 19, and a few others, each shaving off logarithmic factors in the range of 0.1 to 0.5. I'm estimating the contribution from primes beyond 79, where the logarithmic terms decay roughly like p^{-1/2}, and working through whether stacking prime factors alone could push the exponent λ down to the target range—but the numbers suggest I'd need an astronomically large modulus, making this approach impractical at any reachable scale. | | | | Now I'm noticing the observed data shows much larger fluctuations than prime factorization alone can explain: a count of 3 appearing at n ≈ 6.4×10^10 in the deep class, where λ ≈ 10 should give rare but possible Poisson outcomes. This hints that to find a genuine counterexample, I'd need to search through roughly 10^11 members of the deep class—an enormous range—and the same scaling logic applied to the 33-class with λ ≈ 30 would suggest even more extreme behavior there. | | | | Checking the actual expected zeros across the restricted classes: the deep class contributes about 1.2 expected zeros at 10^12, while the 23,7-restricted class with λ ≈ 10.4 and only ~3000 members in that range contributes roughly 0.09, so the dominant signal comes from the deep class's balance between its small Poisson probability and its large population. | | | | Now I'm verifying this against the observed count-1 values by checking their residues modulo the small primes that define each class — for instance, the first observed value 23343989 hits the worst residue mod 5 but not mod 7, so I need to systematically check whether these four examples actually fall into the predicted high-contribution classes. | | | | Given the mixed results, I'm settling on a brute-force scan strategy: search through deep residue classes over large ranges with per-n testing and pruning. The target modulus should be around 2–20 million to balance class sparsity with computational feasibility — something like the product 9·11·17·19·13, which gives roughly 2 million members up to 10^13, allowing me to test each candidate at an average height around 5·10^12. | | | | The complexity estimate is tight but workable: with box sizes around 10^8 per n and aggressive mod-filtering to cut the passing fraction down to 5–10%, the total operation count drops to manageable levels — roughly 1.6·10^13 ops across all candidates, which parallelizes to about 1000 seconds on 16 cores, assuming 2–3 ops per triple check with table lookups organized efficiently. I'm precomputing a mapping from residues to valid k values modulo M to avoid redundant lookups—since each sieve target n mod M gives a single residue r = n − s mod M, I can just look up the corresponding k list rather than iterating through all possibilities for every member. | | | | The key insight is that triangular numbers jump by M² steps within each k-class, which is enormous compared to the search range—so each k-class contributes at most one valid T value. This means for each s, I'm enumerating only a handful of k candidates averaging 2–3 and checking if the resulting n falls within bounds, rather than scanning the entire k-range. | | | | Now I'm estimating the computational cost: for each target class, the work is roughly 1.2 billion operations across 16 cores, taking about 0.1–0.2 seconds per class. Testing the top 1000 worst-case classes modulo 2078505 would take around 75 seconds total, which seems feasible. The marks from these computations are stored efficiently, with negligible per-n overhead. I can iterate over the stored array directly without sorting, which is fine since the order doesn't matter. I need to track the k and M−1−k values for all residue classes modulo M, and while I could skip the count array and just use bit coverage for diagnostics, keeping counts is still useful for tracking. For selecting candidate classes, I'm minimizing the product of factors across the prime divisors of M, and the worst-case residue combinations are limited—so I'll enumerate the top-K classes by predicted λ, computing all possible residue combinations across the modulus components {9,5,11,13,17,19}, which gives 9·5·11·13·17·19 total combinations to evaluate. | | | | I'm deciding whether to include 7 in M—it would increase the modulus to about 14.5M with sparser members but lower λ, but the tradeoff isn't favorable at λ≈13 the gain of 1.22 doesn't justify the cost of ln 7≈1.95 , so I'm sticking with M = 2,078,505. For the range up to 4e12, I expect roughly 1.9 million members per class, so I'll rank the top ~2000 classes by their product of per-prime factors, allowing some second-worst residues at certain primes to balance coverage. | | | | Now I'm checking the Poisson prediction: at the deepest class with λ≈13.6, the expected number of zeros is about 2.3 per class, and across the top 1000 classes with λ up to ~1.3× the deepest , I'd expect tens of zeros total—even if Poisson is off by 100×, I should still find hits. But this raises a sanity check: the same model predicts zeros for class-33 sieve at moderate heights that weren't actually found up to 1e10, so I need to reconcile why the deep classes might behave differently. I need to optimize the per-class computation by precomputing the modular residues once rather than recalculating them for each search, bringing the per-class runtime down to around 1.8 seconds across 16 cores. Once I identify candidate counterexamples, I'll verify each one exhaustively and cross-check with independent symbolic computation to confirm. | | | | Now I'm examining the density distribution within specific windows—looking at class 33 around 1e12, where the sampled members show a minimum count of 4, which seems surprisingly low given the expected Poisson distribution with λ around 13 for that class depth. | | | | I'm also verifying the period calculations for the factor table, particularly for p=17 where I need to confirm that C x,4 mod 17 has the correct period of 17 when accounting for the factorial in the denominator. | | | | For larger primes like p=29 through 79, I'm using P=4096 which introduces a small sampling error around 2%, but that's acceptable for this analysis. For the ranking classes, I need to compute exact per-prime per-residue factor tables, which requires careful handling of when factorials are invertible modulo each prime—noting that 5 and 7 divide certain factorials, so binomial coefficients like C y,6 mod 5 will have different period structures than the simpler cases. | | | | I'm setting up the computation to use period P = p³ for the small primes {3,5,7} and P = p² for 11,13,17,19 to ensure I capture the full periodicity. Then I'm examining how prime powers like 25 compare to their base primes in terms of the worst-case factor values—for instance, class 4 mod 5 splits into subclasses {4,9,14,19,24} mod 25. | | | | The marginal improvement from going to higher prime powers is negligible around 1.6% for mod 25 vs mod 5 , so I'll stick with the simpler moduli. Now I'm ready to implement the core program: it reads target residue classes from a file, generates all S₃ values up to NMAX as an unsorted array with multiplicities, then processes them. | | | | For efficiency, I'm precomputing lookup tables for each residue class—specifically, for every r modulo M, I'm storing which k values satisfy k k+1 /2 ≡ r mod M using a compressed sparse row format. Then for each target class, I iterate through all S₃ values, compute the corresponding residue, and count matches using a byte array indexed by quotient. I'll parallelize across target classes since each thread can maintain its own independent count array without contention. For each residue class km, I'm iterating through k values km, km+M, km+2M, ... up to a maximum determined by the constraint that T = k k+1 /2 stays within bounds. For each k, I compute n = s + T and check if it satisfies the conditions, incrementing a counter at the corresponding index if it does. The cost per s-value is dominated by the list traversal and j-iterations, averaging around 15 nanoseconds per class. Once marking is complete, I scan through the counter array to identify indices with zero counts. I should verify the approach works by testing it against known low-count values, then decide on NMAX—pushing to 1e13 seems feasible given the memory and runtime estimates around 7 minutes across 16 threads for ~2000 classes , and the expected zero counts in the deepest class are small enough that we'd catch them even with the Poisson approximation suggesting only a few expected occurrences. | | | | Now I'm reconsidering the Poisson calculation for the deepest class—the factor of 0.165 I used included constraints on primes up to 79, but we're not actually constraining those, so I need to recalculate the deepest class factor without those prime contributions. | | | | Computing through the product of the remaining factors gives me about 0.2651, which means λ deepest class avg at 10^13 is roughly 22.7. That's catastrophic—e^{-22.7} is essentially 1.4×10^{-10}, and multiplied across 4.8 million class members, I'm getting only 7×10^{-4} expected zeros. But the real problem is that the unconstrained primes 7, 23, 29, 31, and beyond introduce significant variation in λ across members, with the minimum product around 0.5-0.55, so I need to use a mixed Poisson approach where the expected zeros sum over each member's individual e^{-λ} rather than treating λ as constant. | | | | The distribution of X = Π {p∉M} σ p n is roughly log-normal from summing many small independent terms, and the integral for E e^{-22.7X} is dominated by the lower tail—probably somewhere between 10^{-12} and 10^{-14}. Without more precise computation, I need empirical data to calibrate this. Looking at observed counts of n ≤ 2 in the 10^8 to 10^9 range, I'm seeing about 10 per decade globally, but when I try to match this with the mixed-Poisson model using a global λ̄ of around 58 at 10^9, the numbers don't quite align with the class-33 average of 28.34 I measured in that same interval. | | | | Now I'm checking consistency: if the global average is 28.34/0.484 ≈ 58.6, then scaling up to 10^12 should give 58.6 × 1.33 ≈ 78, which matches my earlier estimate. For the observed P cnt ≤ 2 ≈ 2×10^{-8} at 5×10^8, I'm trying to work out whether this comes from the lower tail of X—if X min is around 0.165 the worst case including all primes up to 79 , that occurs with probability roughly 10^{-10}, which seems too rare to explain the observed frequency. | | | | But if moderate values of X around 0.25–0.35 occur with probability 10^{-5} to 10^{-6}, combined with the Poisson tail e^{-15 to -20} ≈ 10^{-7} to 10^{-9}, I'd expect a combined rate around 10^{-13}—far below the observed 2×10^{-8}. This suggests the mixed-Poisson model with independent prime factors is underpredicting the low-count rate by roughly five orders of magnitude, pointing to some structural or Archimedean effect I haven't accounted for, possibly related to how the S3 sums are dominated by a few large terms near critical thresholds. | | | | I'm now wondering if the issue lies in the local factors at p=2: maybe the distribution modulo powers of 2 isn't uniform as the convolution suggested, or perhaps there's a parity structure in the C x,4 mod 2^k terms that I'm missing. Kummer's theorem says C x,4 is odd exactly when the binary digit of x is 1, giving density 1/2, which checks out for mod 2. The convolution of four independent-ish uniform distributions should yield a uniform result, and the triangular structure mod 2^k does seem to support that, but something feels off about the uniformity claim up to 2^10. | | | | Now I'm considering whether the variance actually comes from having very few effective summands at the largest scale: for n around 10^9, x only goes up to about 700, and the dominant term C x,4 ~ n leaves n−C x,4 quite small. The λ heuristic weights contributions by 1/sqrt 2 n−s , which concentrates the mass near s=n, and the r3-count density near n decays like s^{13/24}, so the integral over this region should converge but the local fluctuations in the count of elements in S3 near n might be driving the variance. −s ds with the density function parameterized by a power law, I'm setting up a Beta integral to evaluate the total contribution λ, working through the scaling factors and trying to simplify the expression involving the integral of u^{-11/24} 1−u ^{-1/2}. | | | | Now I'm checking the numerical result against the measured value of 58, which matches. The key insight is that the variance of the indicator sum should follow a Poisson approximation around λ, but there's a crucial complication: the indicators aren't independent because they're correlated through the modular structure of the values. More importantly, many s values in S3 have multiplicities—multiple representations x,y,z can produce the same s—and this multiplicity structure significantly affects how the count accumulates across distinct values. | | | | At scale 1e6, the ratio of total multiplicities to distinct values is about 1.006, which is small, so that's not the main culprit. Let me try a more direct approach: for the known low-count n values, I'll compute their exact λ by examining how "deep" they are in the class structure and calculating their heuristic probability precisely. | | | | I'm building a local heuristic λ loc n that combines the baseline λ̄ n with per-prime class factors σ p, then checking whether this predicts λ values in the 3–6 range mild luck explaining counts of 1–2 or 15–25 requiring implausibly extreme luck, suggesting the model is missing something . I've also empirically pinned down the constant in the λ̄ n = c·n^{1/24} formula to about 24.7. | | I haven't found any counterexamples below 10^10, so now I need to understand what's actually driving certain numbers down to count 1–2 since fixed prime factors alone don't explain the observed frequency. I'll compute local factors for many primes and test my heuristic model against the known low-count cases. | | bash | | | | cd /tmp && python3 << 'EOF' | | import numpy as np | | from math import comb | | import sympy, json | | | | def darr vals,m : | | a=np.zeros m | | for v in vals: a v%m +=1 | | return a/len vals | | def cconv a,b : | | return np.real np.fft.ifft np.fft.fft a np.fft.fft b | | | | exact periods: use P = lcm stuff; safe: for prime p use P = p^2 3 if p==3 else 1 ... | | denominators: 24=2^3 3, 720=2^4 3^2 5, 40320=2^7 3^2 5 7 | | factors = {} modulus - array of f r | | mods = 9,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127 | | for m in mods: | | if m==9: P=3 6 | | elif m in 5,7 : P=m 3 | | else: P=m m | | d4=darr comb x,4 for x in range P ,m | | d6=darr comb y,6 for y in range P ,m | | d8=darr comb z,8 for z in range P ,m | | dt=darr k k+1 //2 for k in range P ,m | | conv=cconv cconv d4,d6 ,cconv d8,dt m | | factors m =conv | | | | np.save '/tmp/factors.npy', np.array None 0, dtype=object | | import pickle | | with open '/tmp/factors.pkl','wb' as f: pickle.dump {m:factors m for m in mods}, f | | | | low = 23343989,1 , 39866594,1 , 54847142,1 , 394239767,1 , 4655,2 , 9590,2 , 24935,2 , 33845,2 , 192080,2 , 2155514,2 , 2962628,2 , 8282657,2 , 48876188,2 , 72755879,2 , 142817024,2 , 152956472,2 , 392829611,2 , 454535519,2 , 498055754,2 , 586266734,2 , 604180652,2 , 674771018,2 , 794743079,2 , 887859740,2 , 936374822,2 | | c = 24.7 | | print "n, cnt, lambda local, product factor" | | for n,cn in low: | | prod=1.0 | | for m in mods: | | prod =factors m n%m | | lam = c n 1/24 prod | | print f"{n} cnt={cn} lam={lam:.2f} prod={prod:.4f}" | | also global stats of prod over random n | | import random | | prods= | | for in range 200000 : | | n=random.randrange 10 9 | | p=1.0 | | for m in mods: p =factors m n%m | | prods.append p | | prods=np.array prods | | print "prod: mean",prods.mean ,"min",prods.min ,"1e-4 quantile",np.quantile prods,1e-4 , "median", np.median prods | | EOF | | | | | | 20 --- TOOL bash --- | | n, cnt, lambda local, product factor | | 23343989 cnt=1 lam=15.72 prod=0.3138 | | 39866594 cnt=1 lam=16.29 prod=0.3181 | | 54847142 cnt=1 lam=17.38 prod=0.3349 | | 394239767 cnt=1 lam=15.91 prod=0.2824 | | 4655 cnt=2 lam=20.52 prod=0.5843 | | 9590 cnt=2 lam=15.74 prod=0.4348 | | 24935 cnt=2 lam=17.72 prod=0.4704 | | 33845 cnt=2 lam=14.80 prod=0.3879 | | 192080 cnt=2 lam=16.68 prod=0.4067 | | 2155514 cnt=2 lam=15.76 prod=0.3474 | | 2962628 cnt=2 lam=20.70 prod=0.4505 | | 8282657 cnt=2 lam=19.19 prod=0.4000 | | 48876188 cnt=2 lam=18.79 prod=0.3639 | | 72755879 cnt=2 lam=21.71 prod=0.4133 | | 142817024 cnt=2 lam=19.30 prod=0.3574 | | 152956472 cnt=2 lam=16.19 prod=0.2989 | | 392829611 cnt=2 lam=21.74 prod=0.3860 | | 454535519 cnt=2 lam=17.10 prod=0.3017 | | 498055754 cnt=2 lam=21.78 prod=0.3829 | | 586266734 cnt=2 lam=19.94 prod=0.3481 | | 604180652 cnt=2 lam=18.78 prod=0.3274 | | 674771018 cnt=2 lam=15.59 prod=0.2705 | | 794743079 cnt=2 lam=18.28 prod=0.3150 | | 887859740 cnt=2 lam=19.60 prod=0.3363 | | 936374822 cnt=2 lam=20.85 prod=0.3569 | | prod: mean 1.000033643112679 min 0.23104683419768643 1e-4 quantile 0.28589878719649287 median 0.9731818362146727 | | | | | | 21 --- ASSISTANT --- | | Looking at the empirical distribution of these candidates, the ones with low local λ values around 15-22 are showing up with counts of 1 or 2, which is much rarer than a Poisson model would predict. The math suggests we'd expect only about 0.2 such cases across the billion-candidate scan, but we're actually observing around 25 instances—roughly a twentyfold discrepancy between the theoretical and observed frequencies. | | | | The issue seems to be overdispersion: the actual count fluctuations are lumpier than Poisson would allow, possibly due to correlated multiplicities. A negative-binomial-like model with some overdispersion factor might fit better, though pushing it too hard like θ=2 would predict far too many zeros. Rather than guessing at the right correction factor, I should directly calibrate against the empirical data by computing the local λ for each candidate in the window files and then fitting the observed count distribution conditional on those λ values using something like negative-binomial regression. | | | | Once I have that fitted model, I can use it to predict expected zeros and optimize the hunt depth and class ranking accordingly. For the candidate enumeration itself, I'm considering whether to stick with the class-based sieve approach or switch to a more direct scan that enumerates all n up to the limit with product of small primes below a threshold—the density of such candidates appears to be around 1e-4 to 1e-5 based on the sample data. | | | | The class-sieve strategy with M = 9·5·11·13·17·19 is actually quite flexible: with K classes, I cover K· NMAX/M members, and the free primes 7, 23, 29, ..., 127 introduce natural variation in the per-member products that gives additional down-fluctuations. I could also consider including 7 or 23 in M itself for more flexibility, though that's a trade-off worth evaluating. | | | | The key question is whether constraining a prime p in M beats using the same budget elsewhere. For each prime, I can calculate whether the density gain factor 1/p outweighs the tail-probability cost exponential in the constraint factor . Running through the numbers at λ~20 and θ~1.5: including 7 gives e^{1.25}≈3.5 but costs a factor of 7, so that's a net loss. Similarly, 23 yields e^{1.44}≈4.2 against a cost of 23—also no. Even 19 looks marginal or slightly negative, and 17 is even worse. So the current choice of M seems well-optimized. | | | | But with λ uncertain—potentially much larger at 1e13 where λ̄ reaches around 86—the marginal analysis shifts. The gain from restricting a prime now depends on λ· 1−f /θ versus ln p , and with higher λ, larger primes might become worth including. I need to recalculate the breakeven points across the full range of λ values to see which primes should actually be in M. The modulus gets astronomically large if I try to use all those primes—the density becomes impractical since I need the total modulus to stay within my constraint of around 1e13. So instead I'm picking a strategic subset of primes with the worst residues, keeping their product under 1e8-1e9 to leave room for the members I need, then ranking them by efficiency the bang-for-buck ratio of 1−f /ln p to minimize the overall product while staying within density limits. Multiplying through the product factors to get approximately 0.214, which gives a final λ around 18.4 adjusted for free prime luck. With about 30,000 members reaching 1e13 and the best candidates gaining an extra factor from free primes in the range 29-127, I'm estimating λ closer to 14.5-15, which under overdispersion yields a near-zero probability. | | | | Considering secondary residue classes could boost λ slightly, though the empirical calibration will ultimately pin down the effective tail behavior. The scaling relationship shows λ̄ growing as n^{1/24}, so at 1e12 I'd expect around 16.8 versus 3000 members—the competing effects of linear member count versus the slowly decaying exponential roughly balance out across the height range, meaning contributions are fairly uniform near the maximum. | | | | Given this uncertainty, I should run empirical calibration first before deciding on the approach. Let me quickly analyze the existing window dumps by computing the local λ for each member count and checking how well the Poisson dispersion fits—that'll tell me whether the model is tracking correctly. | | I've found that the known cnt≤2 values all show λ loc around 15–22, indicating overdispersion relative to Poisson. Now I'll calibrate the conditional distribution P cnt=k|λ loc empirically using the window dumps. | | bash | | | | cd /tmp && ls win .u16 && python3 << 'EOF' | | import numpy as np, pickle | | with open '/tmp/factors.pkl','rb' as f: factors=pickle.load f | | mods=list factors.keys | | c=24.7 | | import struct | | def load fn : | | with open fn,'rb' as f: | | base,M=struct.unpack '<QQ',f.read 16 | | cnt=np.frombuffer f.read 2 M ,dtype=np.uint16 | | return base,M,cnt | | for fn in 'win 900000000 100000000.u16','win 64000000000 100000000.u16','win 1000000000000 200000000.u16' : | | base,M,cnt=load fn | | n=base+33 np.arange M,dtype=np.int64 | | prod=np.ones M | | for m in mods: | | prod =factors m n%m .astype int | | lam=c n.astype float 1/24 prod | | print fn, "corr lam,cnt =",np.corrcoef lam,cnt 0,1 | | bin by lam, look at conditional mean/var and low-count tail | | bins= 0,6,8,10,12,14,17,20,25,30,40,60,1000 | | idx=np.digitize lam,bins | | for b in range 1,len bins : | | sel=idx==b | | ns=sel.sum | | if ns<50: continue | | cm=cnt sel .mean ; cv=cnt sel .var | | lo= cnt sel <=2 .sum ; lo4= cnt sel <=4 .sum | | print f" lam in {bins b-1 },{bins b } : n={ns} mean lam={lam sel .mean :.1f} mean cnt={cm:.2f} var/mean={cv/cm:.2f} P cnt<=2 ={lo/ns:.2e} P cnt<=4 ={lo4/ns:.2e} min={cnt sel .min }" | | EOF | | | | | | 21 --- TOOL bash --- | | win 1000000000000 200000000.u16 | | win 16000000000 100000000.u16 | | win 256000000000 200000000.u16 | | win 4000000000 100000000.u16 | | win 64000000000 100000000.u16 | | win 900000000 100000000.u16 | | win 900000000 100000000.u16 corr lam,cnt = 0.7045680986501222 | | lam in 12,14 : n=165 mean lam=13.6 mean cnt=14.38 var/mean=0.99 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=6 | | lam in 14,17 : n=13456 mean lam=16.2 mean cnt=16.91 var/mean=1.09 P cnt<=2 =0.00e+00 P cnt<=4 =3.72e-04 min=4 | | lam in 17,20 : n=124177 mean lam=18.9 mean cnt=19.38 var/mean=1.10 P cnt<=2 =0.00e+00 P cnt<=4 =4.03e-05 min=3 | | lam in 20,25 : n=778557 mean lam=22.9 mean cnt=23.09 var/mean=1.16 P cnt<=2 =1.28e-06 P cnt<=4 =2.57e-06 min=2 | | lam in 25,30 : n=1063739 mean lam=27.4 mean cnt=27.38 var/mean=1.16 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=5 | | lam in 30,40 : n=943740 mean lam=33.6 mean cnt=33.38 var/mean=1.32 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=9 | | lam in 40,60 : n=106421 mean lam=43.3 mean cnt=43.44 var/mean=1.43 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=16 | | win 64000000000 100000000.u16 corr lam,cnt = 0.7286494562576276 | | lam in 14,17 : n=276 mean lam=16.5 mean cnt=17.04 var/mean=1.11 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=6 | | lam in 17,20 : n=10671 mean lam=19.1 mean cnt=19.54 var/mean=1.03 P cnt<=2 =0.00e+00 P cnt<=4 =9.37e-05 min=3 | | lam in 20,25 : n=218941 mean lam=23.3 mean cnt=23.46 var/mean=1.10 P cnt<=2 =0.00e+00 P cnt<=4 =4.57e-06 min=4 | | lam in 25,30 : n=724304 mean lam=27.8 mean cnt=27.68 var/mean=1.12 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=5 | | lam in 30,40 : n=1555017 mean lam=34.5 mean cnt=33.98 var/mean=1.26 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=9 | | lam in 40,60 : n=517409 mean lam=44.6 mean cnt=43.42 var/mean=1.37 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=14 | | lam in 60,1000 : n=3684 mean lam=62.8 mean cnt=59.65 var/mean=1.14 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=33 | | win 1000000000000 200000000.u16 corr lam,cnt = 0.7618127199651608 | | lam in 17,20 : n=2010 mean lam=19.3 mean cnt=19.41 var/mean=1.10 P cnt<=2 =0.00e+00 P cnt<=4 =4.98e-04 min=4 | | lam in 20,25 : n=117398 mean lam=23.6 mean cnt=23.76 var/mean=1.08 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=6 | | lam in 25,30 : n=737876 mean lam=28.0 mean cnt=28.17 var/mean=1.09 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=6 | | lam in 30,40 : n=3076225 mean lam=35.1 mean cnt=35.09 var/mean=1.25 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=9 | | lam in 40,60 : n=2078430 mean lam=45.7 mean cnt=45.39 var/mean=1.48 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=13 | | lam in 60,1000 : n=48659 mean lam=63.8 mean cnt=62.79 var/mean=1.24 P cnt<=2 =0.00e+00 P cnt<=4 =0.00e+00 min=31 | | | | | | 22 --- ASSISTANT --- | | The calibration looks solid—λ loc is tracking well with the observed means across bins, though there's mild overdispersion around 1.1–1.3 times the mean, likely from within-bin variation and some clustering effects. I'm checking the lower tail behavior now, comparing actual counts against Poisson predictions to see if the model captures rare events correctly. | | | | The Poisson fits are matching remarkably well—even the extreme tail probabilities align when I account for the actual λ values in each bin. This confirms the model is sound; the earlier underprediction was because I hadn't properly accounted for the full range of λ loc variation that exists in the data, including the lower values around 12–14 that appear at moderate frequency. | | | | Now I'm shifting focus to finding zero-count members. The key is that P cnt=0 ≈ e^{-λ loc}, so I need to identify members with the smallest possible λ loc values. I'm computing the minimum achievable λ loc by finding the worst-case product across all primes up to 127, pulling the minimum f values from my earlier table for each prime. | | | | Computing the cumulative product... I'm setting up the optimization model with a cost function that combines a scaling factor for n, fixed prime contributions, and a product over free primes, then computing the expected number of zeros by summing exponential decay across all members — the sieve itself gives us the exact counts we need without additional post-selection. Now I'm plugging in concrete values for λ across different heights, seeing how it scales with n^{1/24} — at 10^10 it's around 17, climbing to 22.5 by 10^13. The X distribution over free primes has mean near zero with tight standard deviation, and empirical samples suggest the minimum free-prime product sits around 0.15 relative to the baseline. The tension is that including more primes gives exponentially better results but increases the computational cost. I'm trying to estimate the expected number of zeros by integrating over the distribution of X values, weighted by their probability—the calculation is dominated by the smallest X values that still have meaningful probability, like X around 0.75 or 0.85, which contribute roughly 1 to 6 expected zeros across the 4.8 million members in the best class. | | | | Now I'm realizing the total expected zeros across all top-K classes might only be 0.01 to 0.05 for the entire 1e13 campaign, which is about 100 times worse than my earlier estimate—the exponential decay at λ around 17-20 is devastating. The only way out is to increase the modulus M by including larger primes like 23, 29, and 31, which would reduce the number of members per class to around 33 but give an exponential gain in sieving efficiency. | | | | With this larger modulus, I'm calculating the filtering factor F and the typical λ value: at 1e13, λ comes out to about 16.8, which gives roughly 3e-7 expected zeros per member. With 33 members per class, that's about 1e-5 per class, requiring 1e5 classes total. But the sieve cost balloons to 2.25 million seconds across 16 cores—completely infeasible. The fundamental issue is that λ stays stubbornly above 15, making the exponential term too small to work with. | | | | Now I'm reconsidering: a full scan of class-33 to 1e13 might actually be doable in 1-2 hours if I account for the actual marking overhead per member. The expected zeros would come primarily from members with smaller local λ values, particularly those where λ loc ≤ 12. | | | | Looking at the empirical data from the 900M range, members in the 12,14 bin are already quite rare, and scaling up to 1e13 makes them even rarer—roughly 3e-6 probability. This suggests around 900k members in that range would contribute about 2 expected zeros, while the 10,12 bin is even sparser at 1e-7 probability. | | | | Pushing down to 1e10, the member count drops to 300M, and the probability for the 12,14 bin is around 4e-5, giving roughly 12k members—yet the empirical searches find nothing up to 1e10, which is puzzling. Accounting for overdispersion variance-to-mean ratio of 1.1–1.3 could boost the tail by 3–10×, pushing expected zeros into the 2–10 range at 1e13, but that still doesn't explain the absence of zeros in the lower range. | | | | The calculation becomes clearer when I factor in the Poisson rate: with λ ≈ 13 at 1e10, the probability of observing a zero drops to e^{-13} × 12k ≈ 0.03, which aligns with finding nothing up to 1e10. Extending the full scan to 1e12 suggests maybe 0.3–1 zero, and to 1e13 perhaps 2–8, which feels plausible. But then I notice something odd: the product constraint at 1e13 with λ loc ≤ 13 implies prod ≤ 0.153, nearly at the absolute minimum of 0.151—yet the probability of prod being that small is around 1e-12, not 3e-6 as the empirical count suggests. There's an inconsistency here that points to the win files sampling only class-33 members, which have a different product distribution than the full population. I'm computing the product of primes in the range 5 through 127 to find the minimum, multiplying step-by-step through the sequence, but I'm noticing a discrepancy with an earlier calculation where the 29-79 range gave approximately 0.043 instead of the 0.77 I was using. | | | | Now I'm refining this with an exponential adjustment factor of about 0.744, which brings the minimum rest probability to around 0.337 — well above the threshold of 0.451-0.526, so this scenario is plausible. A full scan of class-33 up to 10^13 would yield roughly 1-10 expected zeros, making it worth the computational effort of 1.5-2 hours, and it appears to be more efficient per unit cost than selective deep-class scanning since the overhead of scanning individual classes outweighs the cost of a comprehensive sweep. | | | | The full scan requires about 1.05×10^13 marks at 7 nanoseconds each, totaling roughly 74,000 seconds across 16 cores — about 1.3 hours. Block overhead adds another 4 minutes, and memory usage stays manageable: 4GB for thread-local bit arrays, 1.9GB for the S3 lookup table, with the modular reduction computed on-the-fly to save space. Now I'm working out the parallelization strategy across blocks. For a 1e13 block with a k-width around 22,400, I'm getting roughly 680 marks per k-class and about 2.75 classes per residue, which gives around 1,870 marks per s, block pair. Scaling across all 140 blocks and 2.4e8 values of s, the average works out to about 300 marks per s, block , consistent with the total of 1e13 marks I computed earlier. | | | | The lookup overhead is minimal—around 50 nanoseconds for the r lookup plus the isqrt and setup costs, versus 2.1 microseconds for 300 marks at 7 nanoseconds each, so overhead is only about 2.5%. When I output the results, I'm reporting all uncovered members with n ≥ 1, and I've verified that all members below 1e10 are covered, which is a good cross-validation. I'm also noting that class-33 might miss some counterexamples due to modular constraints, but the penalty from the 11-factor makes that case negligible anyway. | | | | Now I'm weighing whether to restrict mod 9 = 5 versus using a mod 99 class restriction—the mod 99 approach saves three times the work but loses some subclasses that contribute exponentially less due to the lambda penalty, so it keeps about 64% of the expected zeros for one-third the cost, which is more efficient overall, though it affects the wall-time to reach 1e13. | | | | Pushing to 3e13 would take 4.5-5 hours with manageable memory at 3.4GB, but the block visits scale to about 20 minutes per core across 16 cores, which is borderline acceptable. I'll start with the 1e13 range first, then continue to 3e13 as a second pass if needed, designing the program to handle chunked runs. | | | | Now I'm thinking through the kernel verification strategy — checking counterexamples at scale 1e12 to 3e13 requires enumerating triples with bounded sums, which balloons to millions of cases that Lean can't feasibly verify directly. I need a smarter approach, probably focusing on finding the smallest counterexample first rather than exhaustive proof. | | | | For the actual Lean decision procedure, I'd iterate through y,z pairs and for each one verify that a specific value m can't be expressed as a positive triangular number by checking all x values up to a bound — but this still requires computing square roots millions of times, and Lean's kernel implementation of Nat.sqrt uses binary recursion without hardware acceleration, making it prohibitively slow. | | | | I could sidestep the sqrt bottleneck by providing a certificate r satisfying r² ≤ v < r+1 ² for each check, but that would require storing roughly 100 million witnesses, which is impractical. An interval-based approach might work — since consecutive x values produce decreasing v values, I could try to batch-verify ranges — but the gaps between consecutive squares at the scale we're working around 10^12 are only about 2 million, while the binomial coefficient C x,3 changes by roughly x³/6 per step, which at x ≈ 2000 is over a billion, so there's no useful monotonicity to exploit there. | | | | I'm reconsidering the whole strategy — maybe swapping which variable plays the primary role would open up a better approach. I'm trying to avoid computing square roots directly by tracking the integer square root incrementally as x increases. For a fixed pair y,z , the value v x decreases monotonically, so its square root also decreases — I can maintain it by scanning downward from the previous value rather than recomputing from scratch. This keeps the total work manageable across all x steps, with the square root value dropping from around 1.5e7 down to small values over roughly 5000 iterations. | | | | But scanning down turns out to be expensive — about 1.5e7 steps per y,z pair, which multiplied across all pairs gives around 6e11 operations, way too slow. Instead, I should use Newton's method to update the square root: from the previous estimate r, compute the next one via a couple of Newton iterations, which converges quadratically. This means roughly 40 divisions per x step across 1.2e8 triples, totaling around 5e9 kernel operations — still potentially slow depending on how fast the underlying big-integer division is. | | | | The real bottleneck is term-level overhead: each division reduction in the kernel takes maybe 0.5 microseconds due to the whnf machinery and pattern matching, which could push the total to around 30 minutes. That's borderline acceptable, though memory usage during the tail-recursive fuel loop with the Nat accumulator is a concern. | | | | I could split this into many smaller lemmas instead — one per y,z -pair, so roughly 40,000 lemmas each running a decide-style loop over x with its own isqrt descent. That would distribute the work to maybe 400+ million operations plus elaboration overhead, which seems more manageable. Let me start with the smallest counterexample and optimize from there. | | | | I should also validate my window-counting logic against the brute-force results I ran earlier. Spot-checking: the value 936374822 has count 2, and it falls in the 900M–1B window where I found exactly one member with count 2 — that matches. The other count-2 member 394239767 is below 900M, so it correctly doesn't appear in that window. The machinery checks out. | | | | Now I'm writing scan33.c to handle the range NLO, NHI with n ≡ 20 mod 33. I need to generate all S3 values up to NHI and track coverage rather than counts — since I only care whether each member is hit at least once, I could theoretically reduce memory by 33× by storing just bits instead of full counts. But the sieve marks all s,k pairs regardless, so I can't exit early per candidate. The tradeoff is whether to deduplicate the S3 list saves some marks but adds overhead or just skip deduplication and scan through duplicates. | | | | For the per-candidate testing approach, I'd iterate through S3 values in descending order from each n, since s values close to n have the highest hit probability ~1/sqrt 2 n−s . The expected number of s values I'd need to check before finding the first hit is surprisingly small — maybe a few hundred at most. I'm estimating the density contribution from s near n using an integral over the probability distribution, which suggests that setting the expected number of hits to around 3 gives me a constraint on the density parameter. | | | | Working through the numbers with density d ≈ 1.3e-5 at 1e13, I get sqrt 2G ≈ 165000, so G ≈ 1.4e10 with about 1.8e5 s-trials per member. But this approach would require roughly 1e5 operations per member across 3e11 members — way too expensive. A sieve-based approach is far more efficient, marking candidates with just 30 operations per member. | | | | For the sieve implementation, I'm organizing it with a bitset block per thread, iterating through s values and handling k-classes modulo 33, with T stepping by ΔT = 33k+561. Memory-wise, storing S3 up to 3e13 takes about 3.4GB in shared memory, which fits. I'm structuring the block bitset by member index j where n = 20 + 33j, with j ranging over j0, j1 . | | | | For each s, block pair, I compute the smallest k in each residue class modulo 33 where T k exceeds the block's lower bound, using a single isqrt per s, km, block . With 2^31 bits per block covering about 2.1e9 members and an n-range of 7.1e10, I need roughly 140 blocks at NHI=1e13. I'm using dynamic scheduling to distribute blocks across threads, then reporting any unset bits corresponding to n ≥ NLO as primes. | | | | I'm also handling edge cases: s can equal n only when T 0 k ≥ 1 , which is guaranteed by the T ≥ 1 constraint, and duplicates in S3 don't affect correctness. For validation, I'll run a scan over 0, 2e9 to confirm full coverage and cross-check against known results, while instrumenting the code to count marked bits. | | | | Now I'm implementing this. | | The calibration checks out—counts follow a Poisson distribution with only mild overdispersion and the tails match well. I'll now run a full scan up to 10^13 for the class n≡20 mod 33 , which should take about 1.5 hours and find roughly 1–10 zeros. | | bash | | | | cat /tmp/scan33.c << 'EOF' | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <string.h | | include <math.h | | include <omp.h | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | typedef int64 t i64; | | static inline u64 isqrt64 u64 x { u64 r= u64 sqrtl long double x ; while r 0&&r r x r--; while r+1 r+1 <=x r++; return r;} | | | | int main int argc,char argv { | | // scan n ≡ 20 mod 33, n in NLO, NHI | | u64 NLO=strtoull argv 1 ,0,10 , NHI=strtoull argv 2 ,0,10 ; | | // S3 generation <= NHI-1 | | u64 NMAX=NHI-1; | | long n4=0,n6=0,n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; n4++;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; n6++;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; n8++;} | | u64 c4=malloc 8 n4 , c6=malloc 8 n6 , c8=malloc 8 n8 ; | | n4=n6=n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; c4 n4++ = u64 v;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; c6 n6++ = u64 v;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; c8 n8++ = u64 v;} | | fprintf stderr,"n4=%ld n6=%ld n8=%ld\n",n4,n6,n8 ; | | long cap=0; | | pragma omp parallel for reduction +:cap | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { if c4 i +c6 j +c8 k NMAX break; cap++;}} | | u64 S3=malloc 8 cap ; long nS3=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { u64 s=c4 i +c6 j +c8 k ; if s NMAX break; S3 nS3++ =s;}} | | fprintf stderr,"|S3|=%ld %.2f GB \n",nS3,nS3 8.0/1e9 ; | | // sort S3 ascending helps block iteration early exit s < R needed ... qsort is slow for 4e8; skip sort, just filter s<R per block full pass each block . | | // k-class lookup mod 33 | | int ks 33 8 , nks 33 ; memset nks,0,sizeof nks ; | | for int k=0;k<33;k++ { int t= k k+1 /2 %33; ks t nks t ++ =k; } | | // members: n = 20 + 33 j ; j in JLO, JHI | | u64 JLO = NLO<=20 ?0: NLO-20+32 /33; | | u64 JHI = NHI<=20 ?0: NHI-20+32 /33; | | const u64 BB = 1ULL<<31; // members per block | | u64 nblocks = JHI-JLO + BB - 1 /BB; | | long nzeros=0; | | pragma omp parallel for schedule dynamic,1 reduction +:nzeros | | for u64 bl=0;bl<nblocks;bl++ { | | u64 j0=JLO+bl BB, j1=j0+BB; if j1 JHI j1=JHI; | | u64 nb=j1-j0; | | u64 nlo = 20+33 j0, nhi = 20+33 j1-1 ; // inclusive member value range | | u64 bits=calloc nb+63 /64,8 ; | | for long i=0;i<nS3;i++ { | | u64 s=S3 i ; | | if s nhi continue; | | int r= int 20 + 33000 - s%33 %33 ; | | u64 tlo = nlo s ? nlo-s : 1; | | u64 thi = nhi-s; | | for int q=0;q<nks r ;q++ { | | int km=ks r q ; | | u64 kmin= isqrt64 8 tlo+1 -1 /2; if kmin<1 kmin=1; | | while kmin kmin+1 /2<tlo kmin++; | | u64 k=kmin + km + 33 - int kmin%33 %33 ; | | u64 t=k k+1 /2; | | if t thi continue; | | u64 j= s+t-20 /33; | | while t<=thi { | | bits j-j0 6 |= 1ULL<< j-j0 &63 ; | | j += k+17; | | t += 33 k+561; | | k += 33; | | } | | } | | } | | for u64 j=j0;j<j1;j++ { | | if bits j-j0 6 j-j0 &63 &1 { | | u64 n=20+33 j; | | if n =NLO && n 0 { | | nzeros++; | | pragma omp critical | | { printf "ZERO %llu\n", unsigned long long n ; fflush stdout ; } | | } | | } | | } | | free bits ; | | pragma omp critical | | fprintf stderr,"block %llu/%llu done\n", unsigned long long bl+1, unsigned long long nblocks ; | | } | | fprintf stderr,"DONE %llu,%llu zeros=%ld\n", unsigned long long NLO, unsigned long long NHI,nzeros ; | | return 0; | | } | | EOF | | gcc -O3 -march=native -fopenmp -o /tmp/scan33 /tmp/scan33.c -lm && echo ok && cd /tmp && time ./scan33 1 2000000000 2 &1 | tail -3 | | | | | | 22 --- TOOL bash --- | | | | real 0m3.764s | | user 0m3.968s | | sys 0m0.020s | | | | ok | | |S3|=2238465 0.02 GB | | block 1/1 done | | DONE 1,2000000000 zeros=0 | | | | | | 23 --- ASSISTANT --- | | The 2e9 test ran successfully in 3.7 seconds, so I'm now planning to extrapolate performance for the full 1e13 range by first timing a smaller interval up to 1e11, then launching the complete scan across all blocks in parallel. With roughly 140 blocks and each requiring 4-8 seconds for a full S3 pass, the total dataset size of 2.4e8 means even a complete iteration per block will take considerable time. | | I'm launching a full scan for numbers congruent to 20 modulo 33 up to 10^13 in the background. | | bash | | | | cd /tmp && nohup ./scan33 1 10000000000000 scan13.out 2 scan13.err & echo launched; sleep 60; grep -c "block" scan13.err; tail -2 scan13.err; cat scan13.out | | | | | | 23 --- TOOL bash --- | | <stdout launched | | </stdout | | <stderr grep: scan13.err: No such file or directory | | tail: cannot open 'scan13.err' for reading: No such file or directory | | cat: scan13.out: No such file or directory | | </stderr | | <returncode 1</returncode | | | | 24 --- ASSISTANT --- | | bash | | | | cd /tmp && ls -la scan13 nohup.out 2 /dev/null; ps aux | grep scan33 | grep -v grep | | | | | | 24 --- TOOL bash --- | | -rw-r--r--. 1 root root 47 Aug 2 19:34 scan13.err | | -rw-r--r--. 1 root root 0 Aug 2 19:34 scan13.out | | root 617 743 4.6 7168528 6061320 ? Rl 19:34 7:50 ./scan33 1 10000000000000 | | | | | | 25 --- ASSISTANT --- | | The computation is running with full resources and CPU usage is climbing—I'll let it continue and monitor progress. While that's working, I'm thinking through the Lean proof strategy for finding a counterexample n₀ likely in the range of 1e12 to 1e13 . The approach is to negate the universal statement and show there exists some n₀ where A306477 n₀ equals zero. | | | | The key insight is that A306477 n counts solutions to the equation w+2 choose 2 + x+3 choose 4 + y+5 choose 6 + z+7 choose 8 = n across all valid w, x, y, z. If A306477 n₀ = 0, then no such solution exists for that particular n₀. The Lean proof would establish that this happens by showing no combination of these binomial coefficients can sum to n₀, which requires checking that for any valid assignment of x, y, z, the remaining value can't be expressed as a triangular number of the required form. So the key insight is that m is representable as a triangular number exactly when 8m+1 is a perfect square of an odd number ≥ 3. For m=0, we have 8m+1=1 which is technically a square, but since 1=2w+3 has no non-negative solution, m=0 is safely excluded. The algorithm checks whether a given m is a counterexample by computing v = 8m+1, taking r = sqrt v , and verifying that r² ≠ v or v = 1. | | | | Writing Lean implementation... Newton's method from an initial guess of n/2 converges in roughly log n iterations—around 45 steps for numbers near 1e12—with each iteration involving division of large numbers that the kernel handles. This means each sqrt call costs around 500-1500 kernel reduction steps, which balloons to 1e10+ steps across millions of triples, still too expensive. I'm thinking about maintaining a monotone descending remainder across the x-loop to avoid recomputing sqrt each time, but need to work out the details. The r-increments across all y,z pairs blow up to around 1e11 operations, which is still too expensive. Sorting all triples by v could work in theory, but verifying the sorted order requires ~1e8 comparisons, and storing 1e8 numbers in the Lean file would be 1.5GB—way too large. The real constraint is that any explicit enumeration in the proof file itself won't scale; the computation has to happen internally within the kernel's evaluation loop. | | | | I need to think about the kernel's actual speed on tight loops—maybe benchmarking something like decide on a large list operation to get a sense of how many primitive reduction steps per second are realistic. If I'm targeting ~1-3 microseconds per step, then a budget of 1e9 steps gives me 20-60 minutes, which is borderline acceptable. For 1e8 triples, I'd need each triple to cost around 10 steps, but computing isqrt via Newton's method alone takes ~150 steps, which already puts me at 1.5e10 total—getting tight. | | | | The key insight is to filter triples more aggressively before the expensive isqrt computation. Using modular arithmetic mod 32 as a cheap pre-filter: triangular numbers mod 32 have only 12 residues out of 32, so roughly 37% of triples would pass. That's not great, but I could try a stronger modulus like powers of 3 or 11 to get better filtering. | | | | Actually, combining filters mod 99 which gives ~24% pass rate and mod 32 37% in sequence drops the overall pass rate to around 9%. That means I'd only need to compute isqrt on about 1e7 triples instead of 1e8, which brings the total runtime down to roughly 2.8 billion operations — tight but probably workable. | | | | For the modular filter itself, I can use a bitmask approach: instead of storing a 99-entry lookup table, I'll use a 99-bit literal and test membership via a kernel shift operation, which is much faster than a list lookup. Then for the triples that pass both filters, I still need to verify whether v=8m+1 is actually a perfect square, so I'll use Newton's method with a good initial seed rather than precomputing anything. | | | | The key insight is that consecutive passing triples in the x-loop have m values that differ significantly at large x, so the seed quality degrades across big jumps. I'm estimating around 3-8 Newton iterations per passing triple on average, with each iteration costing a few kernel operations. This gives roughly 30 steps per passing triple, and the total budget works out: at n₀~1e13 I'm looking at about 1.2 billion operations, and at n₀~1e12 with around 25 million triples, I'm comfortably within budget. | | | | Now I'm refining the triple count at n₀ = 1e12 by accounting for the sum constraint more carefully — the effective box is smaller than the naive bounds suggest, maybe 40% of the full box. The earlier estimate of 6.7e7 triples with multiplicity at 1e12 and 2.4e8 at 1e13 seems right, and I can optimize by breaking early when x-iterations exceed the threshold, which adds negligible cost per y,z pair. | | | | The total kernel cost lands around 8e8 steps, which translates to 15–60 minutes depending on whether each kernel step takes 0.05–0.1 microseconds — I'll need to benchmark to pin that down. For the proof itself, I'm planning to use structural recursion on fuel with explicit Nat state, then rely on rfl to discharge the decidability check: the kernel will fully reduce check n₀ and verify it equals true by reflexivity, and the cost is just the reduction count. | | | | The tricky part is avoiding double evaluation — the elaborator will also try to reduce at elaboration time, which could double the cost. I can't use native decide since it's forbidden, and wrapping it in by decide is worse since that builds a full Decidable instance. My best bet is either accepting the doubling by defining the proof as a theorem with by rfl , or switching to a Nat-based equality check where check n₀ = 1 instead of check n₀ = true — same reduction cost but potentially cleaner. | | | | The elaborator does have fast paths for GMP Nat operations, which helps. But the real bottleneck is kernel reduction of the structural recursion via Nat.rec on fuel — each unfold has overhead from WHNF and motive instantiation, which could add up to microseconds per iteration across 70 million iterations. I should explore a Nat.rec -free formulation or use binary recursion on fuel to reduce depth, similar to how people have verified large prime certificates in the Lean kernel. | | | | Looking at the performance budget: Pratt certificates typically run at around a microsecond per modular multiplication step, so with 1 billion steps I'd need 1000+ seconds. My 70 million loop iterations times 15 steps each gets me to about 1 billion steps — right at the edge. For n₀ at 10^13, that's 2.4 billion triples times 15 steps, pushing into 3.6 billion total steps, which means 1-3 hours in the kernel plus similar elaboration time. That's acceptable within the 72-hour window, but memory is the concern — the kernel's WHNF recursion on deep fuel loops might blow the stack unless the kernel evaluates tail-call reductions iteratively. | | | | I'm thinking about chunking the computation at the theorem level: instead of one massive loop, I'd split it into around 300 lemmas, each verifying a slice of the computation covering 200k-1 million iterations. That keeps the kernel recursion depth manageable, though I need to verify whether the kernel's WHNF actually implements tail recursion as an explicit loop rather than stack-based recursion. | | | | For Nat.rec with literal fuel, the kernel doesn't materialize the full unary representation — it reduces one step at a time, converting the literal into Nat.succ form incrementally, so that's not a blocker. The real question is whether structural recursion in Lean 4 can handle the iteration count without hitting depth limits. | | | | The equation compiler's brecOn approach creates nested product tuples that bloat the kernel, so I need to write the loop function directly using Nat.rec with explicit motive and step functions, ensuring the recursion stays tail-recursive and kernel-friendly. | | | | Now I'm thinking through the kernel's reduction behavior — when Nat.rec unfolds on a successor, it applies the step function to the inductive hypothesis as a closure, which is fine. I should benchmark this on the actual toolchain once I have a working candidate. I also need to be careful about arithmetic operations; the kernel has built-in acceleration for a fixed set of operations like addition, subtraction, multiplication, division, modulo, and bitwise operations, but I'm not sure if Nat.sqrt is in that accelerated list. | | | | My immediate priorities are finding the starting value n₀ the scan is running now and independently testing how fast the Lean kernel can handle a tight loop with division operations — something like 1e7 iterations to see if rfl -style verification is feasible. I should also prepare for the contingency that the scan doesn't find anything below 1e13, in which case I'd extend the search to 3-4e13 or relax the constraint. Let me start setting up the Lean project build. | | The scan is running. I'll verify the Lean project builds and benchmark kernel-reduction speed to prepare for the large computation needed to check the disproof. | | bash | | | | cd /workspace/leanproject && cat lakefile.toml lean-toolchain && ls .lake/packages 2 /dev/null | head | | | | bash | | | | cd /tmp && tail -1 scan13.err; cat scan13.out | | | | | | 25 --- TOOL bash --- | | Copyright 2025 The Formal Conjectures Authors. | | Licensed under the Apache License, Version 2.0 the "License" ; | | you may not use this file except in compliance with the License. | | You may obtain a copy of the License at | | https://www.apache.org/licenses/LICENSE-2.0 | | Unless required by applicable law or agreed to in writing, software | | distributed under the License is distributed on an "AS IS" BASIS, | | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | | See the License for the specific language governing permissions and | | limitations under the License. | | | | name = "formal conjectures" | | keywords = "math" | | defaultTargets = "FormalConjectures" | | testDriver = "FormalConjecturesTest" | | | | leanOptions | | Pretty-prints fun a ↦ b | | pp.unicode.fun = true | | Don't assume a typo is a new variable | | autoImplicit = false | | relaxedAutoImplicit = false | | our own linters which we don't want to force upon downstream packages | | weak.linter.style.copyright.formalConjectures = true | | weak.linter.style.namespace = true | | | | require | | name = "mathlib" | | scope = "leanprover-community" | | rev = "v4.27.0" | | | | We make this a separate library so that we can apply different lean options. | | lean lib | | name = "FormalConjecturesForMathlib" | | | | lean lib | | name = "FormalConjecturesTest" | | lean lib.leanOptions | | Switch off warnings generated by sorry | | warn.sorry = false | | | | lean lib | | name = "FormalConjectures" | | globs = "FormalConjectures.+" | | lean lib.leanOptions | | Switch off warnings generated by sorry | | warn.sorry = false | | our own linters which only make sense for the problems themselves | | weak.linter.style.ams attribute = true | | weak.linter.style.category attribute = true | | weak.linter.style.moduleDocstring = true | | | | lean exe | | name = "extract names" | | srcDir = "scripts" | | root = "extract names" | | exeName = "extract names" | | supportInterpreter = true | | leanprover/lean4:v4.27.0Cli | | LeanSearchClient | | Qq | | aesop | | batteries | | importGraph | | mathlib | | plausible | | proofwidgets | | | | | | 25 --- TOOL bash --- | | |S3|=238659134 1.91 GB | | | | | | 26 --- ASSISTANT --- | | bash | | | | mkdir -p /tmp/kbench && cd /workspace/leanproject && cat /tmp/kbench/KBench.lean << 'EOF' | | -- Benchmark kernel-reduction speed for tight Nat.rec loops with GMP ops. | | -- Model: loop over fuel, each iteration does a few divisions Newton-ish and comparisons. | | | | def step st : Nat : Nat := | | -- a couple of divisions and adds on ~45-bit numbers | | let v := st 3 + 12345678901 | | let r := st + v / st+1 / 2 | | r % 1000000007 + st % 7 + 1 | | | | def loop : Nat → Nat → Nat := | | fun fuel = Nat.rec motive := fun = Nat → Nat | | fun st = st | | fun ih st = ih step st | | fuel | | | | theorem bench : loop 100000 987654321 = 483367222 := by rfl | | EOF | | cp /tmp/kbench/KBench.lean Submission/KBench.lean 2 /dev/null; time env LEAN PATH=$ find .lake -name " .olean" | head -1 | xargs dirname | head -1 lake env lean Submission/KBench.lean 2 &1 | head; | | | | | | 26 --- TOOL bash --- | | | | real 0m7.882s | | user 0m2.412s | | sys 0m0.705s | | | | | | Stack overflow detected. Aborting. | | | | | | 27 --- ASSISTANT --- | | The stack overflow at 100,000 iterations confirms the kernel's elaborator isn't tail-call optimizing this recursive pattern, and the 7.9-second runtime before abort suggests it's choking during reflexivity checking. The solution is to restructure the recursion as a balanced tree rather than a linear chain, so the depth becomes logarithmic instead of linear. | | | | I'd implement this by splitting the iteration range recursively at the midpoint — checking the left half and right half independently, then combining results with conjunction. This requires tracking fuel logarithmic in the bound rather than relying on structural recursion over natural numbers. The kernel's evaluation of the conjunction operator forces left-to-right evaluation, so the stack depth stays proportional to tree depth, which is O log n . The total number of reductions stays the same, but the stack frames drop dramatically. | | | | For the actual computation, each leaf node can recompute its state from scratch given a pure function of the index, so I don't need to thread incremental state through the recursion. The x-loop within each leaf still has linear depth around 2200 frames, but adding the logarithmic overhead from the balanced split should keep the total well under the kernel's stack limit. | | | | However, the Newton iteration for maintaining the square root across the x-loop becomes problematic — the descent in r values across the full range of x can be enormous millions of decrements for large n , so I need to apply Newton updates per x-iteration rather than trying to amortize them across the whole leaf. Estimating the total kernel operations at around 1.2 billion with per-operation costs of 0.2-1μs, which puts the runtime in the 4-20 minute range. I'm exploring whether using Eq.refl true with exact in the elaborator could reduce overhead, though the elaborator's weak-head-normal-form reduction on Nat literals likely carries similar costs. | | | | Looking at established approaches from Mathlib for large kernel computations—like Nat.Prime certificates and polyrith—they rely on Nat.rec -based evaluation with rfl , which the elaborator also reduces but at acceptable levels. I'm considering whether there's a way to bypass elaborator evaluation entirely by structuring the proof term differently, though tactics like exact? and direct proof terms still trigger elaboration. | | | | The core issue is that no matter how I frame the theorem—whether as check = true proved by decide or through of decide eq true —the elaborator must evaluate check at least once to verify the proof, and the kernel evaluates it again. The elaborator's weak-head-normal-form uses fast paths for literal arithmetic similar to the kernel's speed, but the real danger is the whnf cache: with 1e9 steps, caching every distinct intermediate term could trigger catastrophic memory exhaustion. | | | | However, people do successfully run by decide computations up to around 1e7-1e8 steps in the elaborator without hitting OOM, just not at 1e9 scale. The mitigation is to split the computation across 100-1000 separate theorems, each handling 1e6-1e7 steps, so the elaborator's cache gets freed after each declaration and the kernel checks each piece independently, then combine them all into the final lemma. | | | | For the aggregation, I could define a checkChunk function indexed by position, prove each chunk returns true as a separate lemma, then assemble the master proof either by unfolding and rewriting with those chunk lemmas, or by using interval cases or omega to dispatch over the chunk indices and apply the corresponding lemma. | | | | On the verification side, the real work is proving that the optimized checker—with its modular filters, Newton square root approximation, and early exits—correctly establishes that no triple in the chunk satisfies the positive-triangular condition. Rather than proving the filters themselves are correct in isolation, I should design the checker so its return value directly implies the mathematical property we need. | | | | The key insight is leveraging a finite residue check: for each residue class modulo 99, I can verify via decide whether it's in the image of 8·T w +1, then use that to prove the filter semantics—if a residue isn't in the image, no value with that residue can form a valid triangular sum. Then at each leaf of the computation, I check whether the current candidate passes through the filter, and if not, that immediately rules out the triangular condition for that range. Now I'm handling the special case where m=0 which gives v=1 , verifying that the bracket check correctly identifies it as valid since any representation would require T≥1 but we'd have T=0. Then I'm re-deriving the leaf lemma: if v=8m+1 passes either the maskbit test or the bracket check for some r, then no triangular number T w = w+2 w+1 /2 can equal m, which follows from the algebraic identity that T w =m implies 8m+1= 2w+3 ². I'm realizing there's a subtle issue with natural number subtraction when s exceeds n₀. But actually, the logic works out: if s ≥ n₀, then the sum C4+C6+C8 would exceed n₀ regardless of what T is, so no valid representation exists anyway. This means the truncation semantics of natural subtraction align perfectly with the mathematical constraints, so the loops can safely iterate through the full range without needing explicit bounds checks. I can use the monotonicity lemma to optimize the checker: for each y,z pair, I verify once that C4 X+1 plus the other terms exceed n₀, then rely on the monotonicity property to handle all larger x values without rechecking. This cuts the work roughly in half. The overall checker at n₀ ~ 1e12 needs to process around 6.7e7 leaf filters. | | | | I'm reconsidering whether I can drastically cut down the leaves by applying a modular filter at the y,z level first — for fixed y,z , the value M is determined, and x must satisfy a congruence condition modulo q. Most y,z pairs would only have a small subset of x residues passing this filter, so I could enumerate just those instead of checking all x. But precomputing and storing the passing residue lists as certificates would make the file too large, so I'll stick with the uniform approach: iterate through all x values and apply a cheap per-leaf filter of 8-10 operations across the 6.7e7 leaves. | | | | The total operation count comes to roughly 1.1 billion operations, which at 0.3 microseconds per operation translates to about 5.5 minutes for the kernel — acceptable. I'm now exploring a better filter using a single modulus Q = 3168 and a bitmask to test which residues are "square-ish" modulo Q, checking the pass rate by counting odd squares in that range. The mask literal is large but manageable at 69KB in the file, and while shifting such a massive number by variable amounts is expensive—each shift operation copies thousands of 64-bit words—the 0.76% pass rate means we're filtering out so many candidates that the per-leaf work becomes negligible overall. | | | | I'm reconsidering the approach: instead of shifting the full 69KB mask each time, I could use a smaller Q value like 3168, which would shrink the mask to just 396 bytes and make each shift operation much faster microseconds instead of seconds , bringing the total cost for 67 million shifts down to 30-60 seconds while still maintaining a reasonable pass rate of 3% for Newton's method to work on the remaining 2 million leaves. I need to rewrite the kernel benchmark with a balanced recursion tree to avoid the elaboration crash, then measure wall time per leaf as I compute the modulo and bit test operations on a large dataset. | | I've identified that deep linear recursion will cause stack overflow, so I need to switch to balanced divide-and-conquer recursion with O log depth for the kernel loops. Now I'll benchmark this approach. | | bash | | | | cd /tmp && tail -1 scan13.err | | | | bash | | | | cd /workspace/leanproject && cat Submission/KBench.lean << 'EOF' | | -- balanced-tree fold benchmark: check P i for all i in a, a+len , len = 2^fuel | | -- leaf work: one mul, add, mod, shift, land mask bit test , modeled Newton on ~3% of leaves omitted for now | | | | def leaf mask n0 : Nat i : Nat : Bool := | | let v := n0 - i i + 1 -- placeholder arith | | let u := 8 v + 1 % 3168 | | mask u &&& 1 == 1 | not -- bit not set = "filtered out = ok" | | | | -- balanced: fuel-indexed splitting | | def tree mask n0 : Nat : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | fun a = leaf mask n0 a | | fun f ih a = ih a && ih a + 1 <<< f | | fuel | | | | -- mask: some arbitrary 3168-bit-ish literal ~950 digits . Use a computed-ish constant: | | def mask0 : Nat := 2^3168 - 1 / 17 -- big literal after reduction? no—kernel computes each time. Instead inline digits later; this is fine for bench one-time cost . | | | | theorem bench : tree 12345 1000000007 20 0 = true := by rfl | | EOF | | time lake env lean Submission/KBench.lean | | | | | | 27 --- TOOL bash --- | | |S3|=238659134 1.91 GB | | | | | | 27 --- TOOL bash --- | | <stdout Submission/KBench.lean:19:56: error: deterministic timeout at whnf , maximum number of heartbeats 200000 has been reached | | | | Note: Use set option maxHeartbeats <num to set the limit. | | | | Hint: Additional diagnostic information may be available using the set option diagnostics true command. | | </stdout | | <stderr | | real 0m38.319s | | user 0m26.563s | | sys 0m0.669s | | </stderr | | <returncode 1</returncode | | | | 28 --- ASSISTANT --- | | Setting maxHeartbeats to 0 and measuring performance. The scan is taking longer than expected—blocks are massive with 2^31 members each, totaling around 140 blocks, and each one takes roughly 7 minutes to process. I need to verify CPU usage and check the scan progress since S3 generation was slow and blocks are running in parallel, so the first completion messages should appear once the slowest block finishes. | | bash | | | | cd /workspace/leanproject && sed -i 's/theorem bench/set option maxHeartbeats 0 in\ntheorem bench/' Submission/KBench.lean && time lake env lean Submission/KBench.lean | | | | | | 28 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 29 --- ASSISTANT --- | | The benchmark timed out after 5 minutes, which suggests something's wrong with the performance — processing 1 million leaves shouldn't take that long if each operation is just a few microseconds. I'm wondering if the issue is with how mask0 is being computed, though the mask parameter itself seems fine in the test. The leaf operations should be simple enough that this should complete in 1-10 seconds, not exceed the timeout. | | | | Looking deeper, I suspect the culprit is the Nat.rec structure with its motive function. The elaborator's weak head normal form might not handle large literals efficiently, and there's a potential critical bug: when I build the intermediate hypothesis ih as a closure value in the recursor, each time I apply it like ih a && ih a + 2^f , the recursor gets re-evaluated from scratch instead of reusing the partial computation. This means evaluating a leaf at depth 20 re-does the entire chain of recursor unfoldings down 20 levels, and with a million leaves, that's a million times the depth-20 recomputation — the total cost becomes leaves times depth instead of just leaves. | | | | Rough math: 20 levels × 1 million leaves = 20 million recursor unfoldings, each costing 10-30 microseconds in the elaborator motive instantiation is expensive , totaling 200-600 seconds. That's the bottleneck. | | | | The fix is to reduce the depth overhead by increasing the branching factor — say, a 16-way or 64-way tree instead of binary. With a 16-ary tree, I'd only need 5 levels to cover a million nodes, cutting the per-leaf recursor cost dramatically. I'm restructuring the tree to use wider branching, passing the stride width as a computed argument and folding multiple recursive calls per level instead of just two. | | | | Calculating the node count: roughly 1 million leaves divided by 16 per level gives about 70,000 internal nodes total, and each node does one recursor unfold plus 16 applications of the inductive hypothesis — much cheaper than the current approach. So the total recursor unfolds scale with the number of nodes in the binary tree, not the depth — roughly 2× the number of leaves. That means each node's whnf operation must be taking around 150 microseconds or more to account for the 300 second runtime, which seems extraordinarily slow for elaborator reduction. The motive type and the && shortcircuit should be cheap, so maybe the bottleneck is something else: converting the literal Nat.lit 20 to successor form, or possibly a caching blowup in the elaborator causing quadratic subterm re-evaluation. | | | | Let me measure this more precisely by testing smaller fuel values like 14 and 17 to get the per-leaf cost and scaling behavior, and also isolate whether the time is spent in elaborator whnf expensive versus kernel re-checking usually faster . I could also try bypassing elaborator evaluation with Bool.of decide to see if that changes the profile. | | | | The standard approaches like by norm num or by exact Eq.refl true still trigger elaborator unification and whnf, so they don't help. There's a trick from mathlib for heavy kernel computation using Nat.decEq -based reduction, and I'm exploring using conv with rfl to potentially skip some elaborator overhead. | | | | Actually, I just remembered: Lean 4 supports decide +kernel , which bypasses elaborator evaluation entirely and hands the computation directly to the kernel's C++ implementation of whnf — that's much faster and avoids cache bloat. The statement needs to be a Prop with a Decidable instance whose dec field can be reduced by the kernel. | | | | For our tree with 6.7e7 leaves, kernel whnf on primitive Nat operations should run at roughly 0.2-0.5 microseconds per operation, so the total time might be in the ballpark of a second or so. | | | | The kernel recursion depth for a binary tree at fuel 27 is manageable, and term sharing when evaluating ih a && ih a+w shouldn't cause issues since we're just building argument expressions. | | | | I should test decide +kernel on the benchmark with fuel 17 131072 leaves and fuel 20 to measure actual performance, but first I need to check if the previous timed-out command is still running and restart the file if needed. | | I've identified that the elaborator's weak head normal form is the bottleneck, so I'll test using decide +kernel for kernel-only reduction on the balanced tree. | | bash | | | | pkill -f "lean Submission/KBench" 2 /dev/null; cd /workspace/leanproject && cat Submission/KBench.lean << 'EOF' | | def leaf mask n0 : Nat i : Nat : Bool := | | let v := n0 - i i + 1 | | let u := 8 v + 1 % 3168 | | mask u &&& 1 == 0 | | | | def tree mask n0 : Nat : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | fun a = leaf mask n0 a | | fun f ih a = ih a && ih a + 1 <<< f | | fuel | | | | set option maxHeartbeats 0 in | | theorem bench17 : tree 12345 1000000007 17 0 = true := by decide +kernel | | EOF | | time lake env lean Submission/KBench.lean | | | | | | 29 --- TOOL bash --- | | <stdout </stdout | | <stderr Terminated | | </stderr | | <returncode 143</returncode | | | | 30 --- ASSISTANT --- | | The bash calls keep timing out around 4 minutes, which suggests either the fuel limit is too high or the decide +kernel syntax might not be valid in v4.27. I need to test with smaller fuel values and verify the command syntax works before trying again. | | bash | | | | cd /workspace/leanproject && sed -i 's/tree 12345 1000000007 17 0/tree 12345 1000000007 12 0/; s/bench17/bench12/' Submission/KBench.lean && time timeout 120 lake env lean Submission/KBench.lean | | | | | | 30 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 31 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env lean Submission/KBench.lean' /tmp/kb.log 2 &1 & sleep 100; cat /tmp/kb.log; ps aux | grep "lean Submission" | grep -v grep | awk '{print $3, $4}' | | | | | | 31 --- TOOL bash --- | | 0.0 0.0 | | 0.3 0.6 | | 100 4.2 | | | | | | 32 --- ASSISTANT --- | | The CPU is still maxed out even after 100 seconds with 4096 leaves, which suggests something fundamentally wrong with how the kernel is handling this. I'm wondering if the issue is with Nat.rec reduction on literals in the kernel itself, or maybe the decide tactic with kernel reduction is the culprit. Actually, wait — could the whole file elaboration be slow because lake env lean is re-elaborating imports? But there are no imports in this file, so that should be instant. So what's actually taking all this time? Let me trace through what happens with 1 <<< f and see where the bottleneck is. | | | | The bitwise operations like <<< on Nat should be fine, and == uses Nat.beq which is kernel-accelerated. Same with &&& which maps to Nat.land — that's probably GMP-accelerated in the kernel along with other extern ops like add, sub, mul, div, mod, and the bitwise operations. But here's the real issue I'm spotting: when Nat.rec has a motive like fun = Nat → Bool , the recursor's step case receives f as a Nat literal, and the kernel does have a special case to reduce that properly. The real culprit might be sharing loss with exponential blowup — ih appears twice in the step body, and during kernel weak-head-normal-form reduction, Nat.rec gets unfolded every time it's applied without any memoization across branches, which could cause the nodes to explode exponentially. | | | | But wait — with 2^13 nodes for fuel 12, that's only around 4096 leaves and roughly 10,000 unfolds, which should take milliseconds, not hang for over 100 seconds. So something else is definitely broken. The decide tactic with kernel mode might be the issue — it builds the Decidable instance and evaluates decide p by sending it to the kernel, where p is the equality check tree 12345 1000000007 12 0 = true . The Decidable instance construction itself might be where things are getting stuck. | | | | Or maybe the problem is that leaf and tree aren't marked as @ reducible — the kernel should still unfold them fine with regular delta reduction, but there could be something else. Each leaf involves instance projections for HShiftRight.hShiftRight mask u , and while structure projections should reduce cleanly, maybe there's an issue with how the instance path is being resolved. Let me test this more carefully. | | | | I should run a quick sanity check with fuel set to 3 and see how long it takes, then test progressively with more fuel. I'll also try the eval equivalent in the compiler to verify the expected value is correct, and debug interactively if needed. | | I'm finding something is pathologically slow even at 4096 leaves, so I'll bisect with tiny fuels to narrow down the issue. | | bash | | | | pkill -f "lean Submission/KBench"; cd /workspace/leanproject && cat /tmp/kb2.lean << 'EOF' | | def leaf mask n0 : Nat i : Nat : Bool := | | let v := n0 - i i + 1 | | let u := 8 v + 1 % 3168 | | mask u &&& 1 == 0 | | | | def tree mask n0 : Nat : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | fun a = leaf mask n0 a | | fun f ih a = ih a && ih a + 1 <<< f | | fuel | | | | set option maxHeartbeats 400000 in | | theorem bench3 : tree 12345 1000000007 3 0 = true := by decide +kernel | | EOF | | time timeout 60 lake env lean /tmp/kb2.lean; echo "exit $?" | | | | | | 32 --- TOOL bash --- | | <stdout </stdout | | <stderr Terminated | | </stderr | | <returncode 143</returncode | | | | 33 --- ASSISTANT --- | | So the issue isn't about scale—there's something fundamentally non-terminating in the reduction itself. I'm realizing it might be related to how Nat.rec handles the fuel argument and the motive, where the kernel needs the major premise to reduce to a constructor application, but 3 should already be one. | | | | Looking at the reduction chain: when step gets applied, it unfolds into a lambda that recursively calls Nat.rec again, which should work fine. But maybe the real problem isn't the reduction at all—maybe decide is hanging during elaboration or instance synthesis, or possibly lake env lean is recompiling something in the background. The earlier benchmark with 100,000 iterations did run and stack-overflow properly, so the pipeline itself works. The difference now is I'm using bitwise operations like <<< , , &&& , and modulo, which all worked fine before. | | | | Actually, I'm wondering if Nat.shiftRight is the culprit—if it's not GMP-accelerated in the kernel, then something like mask u where u is around 2000 would unfold recursively 2000 times, which shouldn't cause a hang but might be slow. And 8 v + 1 % 3168 with v around a billion should be instant. The timeout was 60 seconds and the process got killed, but the tactic never hit the heartbeat limit, so it's not a deterministic timeout error—it's something else hanging the system. | | | | Wait, the kernel doesn't check heartbeats at all, so kernel reduction is uninterruptible. That means the hang is happening inside kernel reduction itself. I'm looking at Nat.rec with a motive like fun = Nat → Bool , and there's something weird with eta or universe handling. Or maybe it's 1 <<< f where f is a raw Nat variable that gets beta-reduced to a literal. Actually, I think I found it— Bool.and && in the kernel: when reducing ih a && ih b , the kernel should reduce Bool.and x y by pattern matching on x, but something's going wrong there. | | | | Let me think about how Bool.and is actually defined—it's either a pattern match on the first argument or uses Bool.casesOn . Either way it should terminate. But wait, there's also the == comparison on Bool versus Nat—like mask u &&& 1 == 0 which uses Nat.beq . The real way to debug this is to test tiny cases step by step: first just the leaf, then a tree with a trivial leaf that always returns true, then shifts in isolation. I should also try plain decide without kernel mode to see if that terminates, then compare. | | I'm seeing something structural with the leaves hanging at 8, so I'll isolate the components to investigate further. | | bash | | | | cd /workspace/leanproject && for t in "example : 12345 7 &&& 1 == 0 := by decide" "example : 12345 : Nat % 3168 = 2913 := by decide" "def f : Nat → Nat → Bool := fun fuel = Nat.rec motive := fun = Nat → Bool fun = true fun f ih a = ih a && ih a + 1 <<< f fuel | | example : f 3 0 = true := by decide +kernel"; do echo "=== $t"; echo "$t" /tmp/t.lean; timeout 30 lake env lean /tmp/t.lean && echo OK || echo "FAIL/TIMEOUT"; done | | | | | | 33 --- TOOL bash --- | | === example : 12345 7 &&& 1 == 0 := by decide | | OK | | === example : 12345 : Nat % 3168 = 2913 := by decide | | /tmp/t.lean:1:44: error: Tactic decide proved that the proposition | | 12345 % 3168 = 2913 | | is false | | FAIL/TIMEOUT | | === def f : Nat → Nat → Bool := fun fuel = Nat.rec motive := fun = Nat → Bool fun = true fun f ih a = ih a && ih a + 1 <<< f fuel | | example : f 3 0 = true := by decide +kernel | | OK | | | | | | 34 --- ASSISTANT --- | | The tree machinery is working correctly in case 3, though I made an arithmetic error earlier with the modulo calculation. When decide +kernel receives a false proposition, the kernel should reduce to false and trigger a mismatch error quickly, but I'm seeing unexpected behavior—either a hang or something's off with how the short-circuit evaluation is working when a leaf returns false partway through the && chain. | | | | Looking at the leaf computation more carefully: the bit-shift operation 12345 u where u = 8v+1 %3168 can exceed 63, which would zero out the result, making the equality check mostly true. For u < 14 , the bit might be set in 12345, causing false—which should trigger a fast error, not a hang. So maybe bench3 didn't actually hang; perhaps the error message construction or the kernel comparison is taking longer than expected with the 400000 heartbeat limit. Let me rerun bench3 with a longer timeout to see what's actually happening. | | bash | | | | cd /workspace/leanproject && time timeout 120 lake env lean /tmp/kb2.lean; echo "exit=$?" | | | | | | 34 --- TOOL bash --- | | no such file or directory error code: 2 | | file: /tmp/kb2.lean | | | | real 0m0.440s | | user 0m0.300s | | sys 0m0.173s | | | | exit=1 | | | | | | 35 --- ASSISTANT --- | | I'm realizing I may have overwritten the wrong file — I created /tmp/kb2.lean earlier but the loop didn't modify it, and now I'm getting a "no such file" error. Looking back at what happened, I ran pkill -f "lean Submission/KBench" followed by cat /tmp/kb2.lean , so the file should exist, but something went wrong with that command sequence. | | | | Let me just recreate the file and test it again. | | bash | | | | cd /workspace/leanproject && cat /tmp/kb2.lean << 'EOF' | | def leaf mask n0 : Nat i : Nat : Bool := | | let v := n0 - i i + 1 | | let u := 8 v + 1 % 3168 | | mask u &&& 1 == 0 | | | | def tree mask n0 : Nat : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | fun a = leaf mask n0 a | | fun f ih a = ih a && ih a + 1 <<< f | | fuel | | | | theorem bench3 : tree 12345 1000000007 3 0 = true := by decide +kernel | | EOF | | time timeout 120 lake env lean /tmp/kb2.lean; echo "exit=$?" | | | | | | 35 --- TOOL bash --- | | | | real 0m0.626s | | user 0m0.438s | | sys 0m0.224s | | | | exit=0 | | | | | | 36 --- ASSISTANT --- | | Interesting — bench3 runs in 0.6 seconds now, but earlier the same file timed out after 60 seconds. The difference might be related to compiler options like maxHeartbeats or fuel settings from previous runs, or possibly the machine was under heavy load from other processes at that time. | | | | Now I'm planning to scale up the test with higher fuel values 17, 20 and measure performance while accepting that scan33 is still consuming CPU resources, maybe running the benchmarks with nice to see how they behave under contention. | | The test passes in 0.6s—the earlier hangs were from CPU starvation during the background scan. Now I'll properly scale-test fuel 17/20. | | bash | | | | cd /tmp && tail -1 scan13.err; cd /workspace/leanproject && sed 's/tree 12345 1000000007 3 0/tree 12345 1000000007 17 0/; s/bench3/b17/' /tmp/kb2.lean /tmp/kb17.lean && time timeout 600 lake env lean /tmp/kb17.lean; echo "exit=$?" | | | | | | 36 --- TOOL bash --- | | | | real 0m24.849s | | user 0m24.052s | | sys 0m0.840s | | | | |S3|=238659134 1.91 GB | | exit=0 | | | | | | 37 --- ASSISTANT --- | | Looking at the performance metrics from this test run, I'm seeing 190 microseconds per leaf which is way too slow—that would stretch to hours for millions of leaves. I need to figure out whether the kernel or elaborator is the bottleneck here. | | | | The issue is that decide+kernel might be double-evaluating: the tactic calls evalDecideCore with kernel mode enabled, which uses Lean.Kernel.isDefEq , but it could still be doing a whnf pass through the elaborator first to check the result, then again in the kernel to certify it. My leaf instances involve long projection chains through shift operations and arithmetic, each unfolding to maybe 100+ primitive reductions, and if each reduction costs 1-2 microseconds in the kernel due to expression allocation and hashing, that accounts for the observed slowdown. | | | | To fix this, I could batch the work—instead of deciding each leaf independently, I could make each leaf handle a small strip of x values at once, reducing the per-leaf overhead. | | | | Or I could bypass the typeclass machinery entirely and call the primitive operations like Nat.shiftRight , Nat.land , Nat.mod , Nat.beq directly, skipping the instance projection chains—that alone could save 5-15 unfoldings per operation and give a 2-5× speedup. | | | | Better yet, I could reduce the number of operations per x value by combining the filter logic more cleverly. Since the filter 8 v+1 % 3168 is determined entirely by v % 396 because of the gcd relationship , I can precompute a bitmask over the 396 residue classes and then just do a mask lookup and bit check instead of the full modular arithmetic. | | | | The real bottleneck though is the sheer number of leaves being tested. For any fixed y,z pair, the value v must satisfy a modular constraint that only passes about 3% of the time, so I should precompute a per- y,z certificate that lets me skip most x values entirely. | | | | The key insight is that C₄ x mod 396 has a periodic structure in x — instead of testing every x individually, I can iterate over residue classes modulo the period, determine which classes pass the filter once, and then only expand those passing classes into individual x values. This cuts the leaf count down to roughly 3% of the original, with just the overhead of checking the period structure for each y,z . | | | | But computing the actual period is tricky: since 396 = 4·9·11 and we're dividing by 24, the period involves lcm calculations that might push it to 2376 or even 4752 — larger than the x-range of ~2200, so there's no repetition to exploit. This approach isn't working out. | | | | Let me try a different angle: a two-level filter where the first test is cheap and eliminates most x values with just a couple of operations, like checking v mod 32 against a small lookup table of valid residues. Wait, I'm realizing the mod-32 test is actually perfect for odd squares—all odd squares mod 32 are exactly {1,9,17,25}, which are all of the form 8k+1, so this filter passes everything and gives no information. But looking at mod-256, I need to trace through the triangular number residues that appear when decomposing 2t+1 ² into the form 8T t +1. | | | | Rather than manually enumerate all the triangular residues mod 32, I should just compute this numerically later and design the filtering masks directly on the v-residues themselves—this avoids the 8v+1 transformation trick since checking m ≡ T mod q is equivalent to checking 8m+1 ≡ odd-square mod 8q anyway. | | | | For the optimal cost filter, I'm using a single modulo operation with Q around 3168 which is 2^5 · 9 · 11 , then applying a bitmask. The density of triangular residues mod 3168 factors as the product of densities mod 32, mod 9, and mod 11—roughly 4/9 for mod 9 and 6/11 for mod 11. I'm computing the exact image of triangular numbers mod 32 by checking T 0 through T 63. | | | | Interestingly, triangular numbers mod powers of 2 actually cover all residues—this explains why there's no effective 2-adic filter. So the best approach is to build Q from odd primes: 9, 11, 25, 49, 13, 17, 19, 23, where each prime p contributes a pass rate of roughly p+1 / 2p , which is about 1/2 per prime. I'm now examining how triangular numbers distribute mod each of these primes. Compiling the pass rates for each modulus and multiplying them together to estimate the overall filtering power—the product drops rapidly as I chain more constraints, reaching around 1-2% after combining moduli 27, 11, 25, 49, 13, 17, and 19. | | | | The naive approach of creating a single mask for the product Q ≈ 1.5 billion is infeasible due to memory constraints, so I'm splitting this into sequential tests: first checking candidates against Q₁ = 27·11·25 = 7425 with a manageable ~1KB bitmask, then applying subsequent modular filters to the survivors. The pipeline processes each candidate through modular filters: first checking divisibility by 7425 passing ~7% , then applying a second filter on survivors using modulo 10829 narrowing to ~1% , and finally a Newton bracket check. Each candidate requires roughly 5 primitive operations plus overhead from the recursive tree structure, totaling maybe 12-20 reductions per leaf, though the actual bottleneck is reduction overhead rather than operation count—even optimized direct calls might only drop us from 190μs to 50-70μs per leaf. | | | | With 6.7 million candidates, that's roughly 4700 seconds or about 1.3 hours on a single core just for kernel evaluation. The elaborator doesn't evaluate the Decidable instance when using decide +kernel kernel-only reduction , but Lean 4 doesn't parallelize elaboration within a single file by default in the CLI, so everything runs sequentially. | | | | I'm thinking 1-2 hours total is acceptable for now, though I could optimize later by splitting the z-ranges across roughly 40 lemmas. Another approach is to batch x-values into strips of 4 in the leaf nodes — combining them with explicit conjunctions to amortize the tree-node overhead and potentially save around 30%. | | | | The kernel approach seems feasible as long as the counterexample n₀ stays below roughly 2 trillion to keep the triple count under 100 million. Still waiting on the scan13 progress to complete a block. | | | | Now I'm looking at the performance metrics — S3 has 238 million entries, and I'm calculating marks per block. With roughly 3 trillion total marks across all members and 140 blocks, that's about 75 billion marks per block. At 300 million marks per second per core, each block takes around 250 seconds per thread, and with 16 threads handling 140 blocks in 9 rounds, the first batch should finish in 250–400 seconds. | | | | But wait — the bits array is 256MB with random access patterns, and each mark operation triggers a cache miss at ~90 nanoseconds. That's 74 billion marks times 90 nanoseconds per block, which balloons to over 6600 seconds per block. Across 140 blocks split among 16 threads, that's potentially 16 hours total — way too slow. | | | | I need to rethink the marking strategy with cache locality in mind. The idea is to sub-block the bitset into smaller chunks that fit in L2 cache — maybe 1MB or 4MB chunks — so I can process each T-range within a sub-block before moving to the next one. This trades some setup overhead repeating the isqrt and class loop for each sub-block for much better cache behavior. The math is tight though: 140 blocks times roughly 35,000 sub-blocks of 1MB each, with setup costs around 20 nanoseconds per sub-block... it might just barely fit within the time budget if I'm careful about the inner loop structure. | | | | The real issue is that keeping s as the outer loop causes writes to jump around wildly — each mark lands millions of members apart, which is inherently random access. So I'm considering a different approach: bucket the marks by sub-block first using radix binning, then write them sequentially within each bucket. That way the writes stay cache-friendly and sequential instead of scattered. I'm considering an alternative approach to reduce the total marks needed by using early-exit semantics — since we only need to mark each member once on its first hit , I could split the sieve into phases: first mark using only the densest or cheapest subset of s values to get most members covered quickly, then handle the remaining unmarked members in a second phase. The expected trials to hit a survivor scales with the probability density, working out to around 1.8e5 trials to accumulate the needed hits. That puts the total computation at roughly 2.7e8 survivors times 1e5 trials — way too much. I could reduce the workload by restricting to a modular subclass, cutting the member count and marks by about two-thirds, which would bring the runtime down to around 5-6 hours while preserving most of the expected hits. | | | | With mod-99 filtering and bucketed cache-friendly marking, I'm looking at roughly 3.5e12 marks instead of the original 1e13, running at 5-8 nanoseconds per mark. That's 21,000 seconds total, which across 16 threads drops to about 22 minutes — a huge win. Adding in the S3 passes and setup overhead, I should be able to complete this in under an hour. each bucket's marks atomically into the shared bitset, avoiding contention by having threads work on disjoint s-ranges and flush their private bucket buffers independently. Each s-batch processes around 3.2e8 marks across 16 threads, then flushes in parallel over 1024 buckets with minimal overhead from barriers and segment headers. That gives roughly 11,000 batches total, which is manageable. I'm torn between running the current scan33 16 hours versus writing the faster mod-99 version — given the 72-hour budget, I should go ahead and implement the optimized version rather than wait. | | | | For validation, I'll compare the new mod-99 variant against scan33 on a subset like 1, 2e9 , checking that marked bitsets match and total mark counts align. I can also run both on 0, 2e9 and cross-check per-member coverage bits to catch any discrepancies. Though I'm realizing the mod-99 approach discards subclasses 2 and 8, which I need to account for. | | | | The tradeoff seems reasonable since those subclasses carry about 36% of expected zeros. Rather than targeting 1e13 immediately, I'll start with 1e10, 4e12 to get a quick result in ~10 minutes, then decide whether to push further. At 1e13, the kernel proof would take around 3.3 hours with the x-leaves computation, which is manageable. I should also separately scan the discarded subclasses mod 9 to ensure I'm not missing coverage. | | | | Before diving into scan99.c, I need to verify the Lean literal size for Q1—about 2240 decimal digits, which is fine. There's also a potential optimization: instead of complex bucketing, keep the block bitset small enough for L2/L3 cache and reduce S3 passes by tracking state per s, k-class pair, though that would require ~8GB for state storage. | | | | The real bottleneck is random access to marks in a 1GB bitset—even with 16 threads, that's around 5.5 hours without bucketing. With bucketing, it drops to 30-45 minutes, so the bucketing approach is worth the added complexity. | | The full scan would take about 16 hours due to cache issues, so I'm restricting to the subclass n≡86 mod 99 to keep roughly two-thirds of the expected zeros while reducing the cost to a third, and I'll use radix-bucketed cache-friendly marking instead. | | bash | | | | pkill -f scan33; cat /tmp/scan99.c << 'EOF' | | // Scan n ≡ 86 mod 99 for A306477 n =0, n in NLO,NHI , cache-friendly bucketed marking. | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <string.h | | include <math.h | | include <omp.h | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | typedef uint32 t u32; | | static inline u64 isqrt64 u64 x { u64 r= u64 sqrtl long double x ; while r 0&&r r x r--; while r+1 r+1 <=x r++; return r;} | | | | define MOD 99 | | define RES 86 | | | | int main int argc,char argv { | | u64 NLO=strtoull argv 1 ,0,10 , NHI=strtoull argv 2 ,0,10 ; | | u64 NMAX=NHI-1; | | long n4=0,n6=0,n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; n4++;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; n6++;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; n8++;} | | u64 c4=malloc 8 n4 , c6=malloc 8 n6 , c8=malloc 8 n8 ; | | n4=n6=n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; c4 n4++ = u64 v;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; c6 n6++ = u64 v;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; c8 n8++ = u64 v;} | | long cap=0; | | pragma omp parallel for reduction +:cap | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { if c4 i +c6 j +c8 k NMAX break; cap++;}} | | u64 S3=malloc 8 cap ; long nS3=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { u64 s=c4 i +c6 j +c8 k ; if s NMAX break; S3 nS3++ =s;}} | | fprintf stderr,"|S3|=%ld %.2f GB n4=%ld n6=%ld n8=%ld\n",nS3,nS3 8.0/1e9,n4,n6,n8 ; | | // k-class lookup mod 99: T k mod 99 depends on k mod 99 | | int ks 99 12 , nks 99 ; memset nks,0,sizeof nks ; | | for int k=0;k<99;k++ { int t= int u64 k k+1 /2 %99 ; if nks t <12 ks t nks t ++ =k; } | | // members: n = RES + 99 j | | u64 JLO = NLO<=RES ?0: NLO-RES+98 /99; | | u64 JHI = NHI<=RES ?0: NHI-RES+98 /99; | | const u64 BB = 1ULL<<33; // members per big block bitset 1GB | | const int LOGBUCKET = 23; // members per bucket bitset 1MB | | u64 nblocks= JHI-JLO+BB-1 /BB; | | long nzeros=0; | | u64 bits=malloc BB/8 ; | | int NT=omp get max threads ; | | // per-thread bucket buffers | | const long BUFCAP = 4L<<20; // marks per thread per batch | | u32 buf=malloc NT sizeof void ; | | long bufn=calloc NT,8 ; | | for int t=0;t<NT;t++ buf t =malloc 4 BUFCAP ; | | // batch s-ranges: process S3 in slices so buffers don't overflow | | for u64 bl=0;bl<nblocks;bl++ { | | u64 j0=JLO+bl BB, j1=j0+BB; if j1 JHI j1=JHI; | | u64 nb=j1-j0; | | memset bits,0, nb+63 /64 8 ; | | u64 nlo=RES+99 j0, nhi=RES+99 j1-1 ; | | long done=0; | | long SLICE = 2000000; // s per slice per thread- marks bounded... adaptive below | | while done<nS3 { | | long hi=done+SLICE NT; if hi nS3 hi=nS3; | | pragma omp parallel | | { | | int tid=omp get thread num ; | | u32 B=buf tid ; long bn=0; | | pragma omp for schedule dynamic,4096 nowait | | for long i=done;i<hi;i++ { | | u64 s=S3 i ; | | if s nhi continue; | | int r= int RES + 99 100000 - s%99 %99 ; | | u64 tlo= nlo s ?nlo-s:1; | | u64 thi=nhi-s; | | for int q=0;q<nks r ;q++ { | | int km=ks r q ; | | u64 kmin= isqrt64 8 tlo+1 -1 /2; if kmin<1 kmin=1; | | while kmin kmin+1 /2<tlo kmin++; | | u64 k=kmin+ km+99- int kmin%99 %99 ; | | u64 t=k k+1 /2; | | while t<=thi { | | u64 j= s+t-RES /99 - j0; | | if bn<BUFCAP B bn++ = u32 j LOGBUCKET <<LOGBUCKET LOGBUCKET ; else break; // placeholder, fixed below | | // store full j 33 bits as two parts? simpler: j < 2^33; store j 3 in u32? loses bits. | | t+=99 k+4950; k+=99; | | } | | } | | } | | bufn tid =bn; | | } | | // PROBLEM: u32 can't hold 33-bit j. Fix: use u64 buffers? memory 2x. Simplify: BB=1<<32 members bitset 512MB , j fits u32. | | fprintf stderr,"INTERNAL ERROR: should not use this binary\n" ; exit 1 ; | | } | | } | | return 0; | | } | | EOF | | echo "draft has a design bug u32 vs 33-bit ; rewriting with BB=2^32" | | | | | | 37 --- TOOL bash --- | | <stdout </stdout | | <stderr Terminated | | </stderr | | <returncode 143</returncode | | | | 38 --- ASSISTANT --- | | I see the issue — pkill with the -f flag matched the bash process itself since the command line contained "scan33", so it killed our own shell. I need to use pkill with a more specific pattern or exact process name to avoid this self-termination. | | bash | | | | pkill -x scan33; sleep 1; ps aux | grep -c " s can33"; ls -la /tmp/scan99.c 2 /dev/null | head -2 | | | | | | 38 --- TOOL bash --- | | 2 | | | | | | 39 --- ASSISTANT --- | | bash | | | | ps aux | grep " s can33"; pkill -9 -x scan33; sleep 1; ps aux | grep " s can33"; echo done | | | | | | 39 --- TOOL bash --- | | root 1481 0.0 0.0 2500 1544 ? S 19:54 0:00 timeout -k 5s 300s bash --login -c ps aux | grep " s can33"; pkill -9 -x scan33; sleep 1; ps aux | grep " s can33"; echo done | | root 1482 0.0 0.0 3932 3176 ? S 19:54 0:00 bash --login -c ps aux | grep " s can33"; pkill -9 -x scan33; sleep 1; ps aux | grep " s can33"; echo done | | root 1481 0.0 0.0 2500 1544 ? S 19:54 0:00 timeout -k 5s 300s bash --login -c ps aux | grep " s can33"; pkill -9 -x scan33; sleep 1; ps aux | grep " s can33"; echo done | | root 1482 0.0 0.0 3932 3180 ? S 19:54 0:00 bash --login -c ps aux | grep " s can33"; pkill -9 -x scan33; sleep 1; ps aux | grep " s can33"; echo done | | done | | | | | | 40 --- ASSISTANT --- | | Good, scan33 is already dead from the earlier accidental pkill. I notice my bash tool calls run under a 300-second timeout with a 5-second kill grace period, so longer jobs need to use nohup in the background. Now I'm writing scan99.c with a bitset of 512MB per block 2^32 members , where j fits in a 32-bit unsigned integer. For blocks up to 1e13, I need roughly 1.01e11 members total, which determines the block structure. | | | | I'm designing the threading strategy: each thread maintains per-bucket buffers 512 buckets per block, each bucket holding ~32K marks in a vector . When a vector fills, the thread flushes it directly to the bitset using atomic OR operations, keeping the working set bucket-local and cache-friendly. This avoids global synchronization—each thread flushes independently per bucket. The memory footprint is reasonable: 512 vectors × 32K capacity × 4 bytes per thread = 64MB per thread, totaling about 1GB for 16 threads. During a flush burst of 32K marks within a 1MB bucket region, the atomic contention stays low since the target lines are likely already in L2 cache. | | | | Now I'm working through the cost model: with roughly 2.8e8 marks per bucket per block, that's about 8800 flush cycles per bucket. If each flush reloads the 1MB bucket region from RAM ~30μs , that's 0.26 seconds per bucket, scaling to ~135 seconds per block across all 512 buckets—acceptable overhead. Increasing the flush vector size to 64K marks would halve the reload cost while keeping memory usage under 2GB, which is a good trade-off. I'm leaning toward keeping the atomic OR approach rather than switching to a two-phase disk-based binning strategy, since the current design is simpler and the performance is adequate. | | | | Exploring a cleaner approach: if I set the bucket size to 256KB 2^21 members , the reload cost drops to ~8μs per flush. With 16K-mark vectors across 2048 buckets, that's roughly 4460 flushes per bucket, totaling about 73 seconds per block—well within budget. The per-thread buffer overhead would be 128MB, scaling to 2GB total, which is borderline but workable. Alternatively, bumping the bucket size to 512KB 2^22 members with 16K-mark vectors keeps per-thread buffers at 64MB while maintaining similar flush costs. | | | | Scaling up the mark vector to 64K entries reduces flush overhead by a factor of four, bringing the total runtime down to around 14 minutes when accounting for mark generation and S3 passes across all 24 blocks. There's a detail about j overflow relative to j0 that needs handling. | | | | For the implementation, I'm using atomic operations to set bits in a flush bitmap for each mark, then scanning for zeros in parallel after each block completes. For validation mode, I'm considering whether to support MOD and RES parameters—making them compile-time constants but also accepting runtime arguments through globals, with the modular arithmetic working out since 99 is odd. | | | | Now I'll write the code and benchmark it on the range 1, 5e9 to verify correctness and measure performance, also printing the total mark count as a sanity check against the estimate. | | scan33 is dead but that's fine since it's superseded anyway. I'll now set up the proper bucketed scanner, keeping in mind that bash calls have a 300-second limit so longer jobs need to run via nohup. | | bash | | | | cat /tmp/scan99.c << 'EOF' | | // Scan n ≡ 86 mod 99 for A306477 n =0, n in NLO,NHI . Bucketed marking. | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <string.h | | include <math.h | | include <omp.h | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | typedef uint32 t u32; | | static inline u64 isqrt64 u64 x { u64 r= u64 sqrtl long double x ; while r 0&&r r x r--; while r+1 r+1 <=x r++; return r;} | | define MOD 99ULL | | define RES 86ULL | | define LOGB 22 // members per bucket = 2^22 bitset 512KB | | define VCAP 65536 // marks per vector | | | | int main int argc,char argv { | | u64 NLO=strtoull argv 1 ,0,10 , NHI=strtoull argv 2 ,0,10 ; | | u64 NMAX=NHI-1; | | long n4=0,n6=0,n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; n4++;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; n6++;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; n8++;} | | u64 c4=malloc 8 n4 , c6=malloc 8 n6 , c8=malloc 8 n8 ; | | n4=n6=n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; c4 n4++ = u64 v;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; c6 n6++ = u64 v;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; c8 n8++ = u64 v;} | | long cap=0; | | pragma omp parallel for reduction +:cap | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { if c4 i +c6 j +c8 k NMAX break; cap++;}} | | u64 S3=malloc 8 cap ; long nS3=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { u64 s=c4 i +c6 j +c8 k ; if s NMAX break; S3 nS3++ =s;}} | | fprintf stderr,"|S3|=%ld %.2f GB \n",nS3,nS3 8.0/1e9 ; | | int ks 99 12 , nks 99 ; memset nks,0,sizeof nks ; | | for int k=0;k<99;k++ { int t= int u64 k k+1 /2 %99 ; ks t nks t ++ =k; } | | u64 JLO= NLO<=RES ?0: NLO-RES+MOD-1 /MOD; | | u64 JHI= NHI<=RES ?0: NHI-RES+MOD-1 /MOD; | | const u64 BB=1ULL<<32; | | u64 nblocks= JHI-JLO+BB-1 /BB; | | u64 bits=malloc BB/8 ; | | int NT=omp get max threads ; | | long totzeros=0; unsigned long long totmarks=0; | | for u64 bl=0;bl<nblocks;bl++ { | | u64 j0=JLO+bl BB, j1=j0+BB; if j1 JHI j1=JHI; | | u64 nb=j1-j0; | | u64 nwords= nb+63 /64; | | pragma omp parallel for | | for u64 w=0;w<nwords;w++ bits w =0; | | u64 nlo=RES+MOD j0, nhi=RES+MOD j1-1 ; | | u64 nbuck= nb+ 1ULL<<LOGB -1 LOGB; | | unsigned long long blockmarks=0; | | pragma omp parallel reduction +:blockmarks | | { | | u32 vec=malloc size t nbuck VCAP 4 ; | | int vn=calloc nbuck,sizeof int ; | | pragma omp for schedule dynamic,8192 nowait | | for long i=0;i<nS3;i++ { | | u64 s=S3 i ; | | if s nhi continue; | | int r= int RES+MOD 2000ULL-s%MOD %MOD ; | | u64 tlo= nlo s ?nlo-s:1; | | u64 thi=nhi-s; | | for int q=0;q<nks r ;q++ { | | int km=ks r q ; | | u64 kmin= isqrt64 8 tlo+1 -1 /2; if kmin<1 kmin=1; | | while kmin kmin+1 /2<tlo kmin++; | | u64 k=kmin+ km+ int MOD- int kmin%MOD %MOD ; | | u64 t=k k+1 /2; | | while t<=thi { | | u64 j= s+t-RES /MOD - j0; | | u64 bkt=j LOGB; | | int pn=&vn bkt ; | | vec bkt VCAP + pn ++ = u32 j; | | blockmarks++; | | if pn==VCAP { | | u32 V=&vec bkt VCAP ; | | for int q2=0;q2<VCAP;q2++ { u64 jj=V q2 ; atomic fetch or &bits jj 6 ,1ULL<< jj&63 , ATOMIC RELAXED ; } | | pn=0; | | } | | t+=MOD k+MOD MOD+1 /2; k+=MOD; | | } | | } | | } | | // flush residuals | | for u64 b=0;b<nbuck;b++ { | | u32 V=&vec b VCAP ; | | for int q2=0;q2<vn b ;q2++ { u64 jj=V q2 ; atomic fetch or &bits jj 6 ,1ULL<< jj&63 , ATOMIC RELAXED ; } | | } | | free vec ; free vn ; | | } | | totmarks+=blockmarks; | | long z=0; | | pragma omp parallel for reduction +:z | | for u64 j=0;j<nb;j++ { | | if bits j 6 j&63 &1 { | | u64 n=RES+MOD j0+j ; | | if n =NLO { z++; | | pragma omp critical | | { printf "ZERO %llu\n", unsigned long long n ; fflush stdout ; } | | } | | } | | } | | totzeros+=z; | | fprintf stderr,"block %llu/%llu done marks=%llu zeros=%ld\n", unsigned long long bl+1, unsigned long long nblocks,blockmarks,z ; | | } | | fprintf stderr,"DONE %llu,%llu zeros=%ld totmarks=%llu\n", unsigned long long NLO, unsigned long long NHI,totzeros,totmarks ; | | return 0; | | } | | EOF | | gcc -O3 -march=native -fopenmp -o /tmp/scan99 /tmp/scan99.c -lm && cd /tmp && time ./scan99 1 5000000000 2 &1 | tail -4 | | | | | | 40 --- TOOL bash --- | | | | real 0m1.785s | | user 0m16.514s | | sys 0m0.059s | | | | |S3|=3706729 0.03 GB | | block 1/1 done marks=1351897102 zeros=0 | | DONE 1,5000000000 zeros=0 totmarks=1351897102 | | | | | | 41 --- ASSISTANT --- | | I'm working through some performance calculations—looking at mark generation rates and trying to project scaling behavior up to 1e13 marks, though the math is getting a bit tangled with the exponent conversions. | | 5×10⁹ in 1.8s. Launching the full run to $10^{13}$ ~30–40 min . | | bash | | | | cd /tmp && nohup ./scan99 1 10000000000000 scan99.out 2 scan99.err & sleep 5; tail -1 scan99.err | | | | | | 41 --- TOOL bash --- | | <stdout </stdout | | <stderr tail: cannot open 'scan99.err' for reading: No such file or directory | | </stderr | | <returncode 1</returncode | | | | 42 --- ASSISTANT --- | | bash | | | | sleep 30; cd /tmp && ls -la scan99. ; tail -2 scan99.err 2 /dev/null; ps aux | grep " s can99" | awk '{print $3,$4}' | | | | | | 42 --- TOOL bash --- | | -rw-r--r--. 1 root root 4516 Aug 2 19:55 scan99.c | | -rw-r--r--. 1 root root 25 Aug 2 19:55 scan99.err | | -rw-r--r--. 1 root root 0 Aug 2 19:55 scan99.out | | |S3|=238659134 1.91 GB | | 0.0 0.0 | | 691 5.0 | | 0.0 0.0 | | 0.0 0.0 | | | | | | 43 --- ASSISTANT --- | | While the code compiles, I'm now working through the detailed Lean architecture for the submission, which will involve removing the original conjecture and replacing it with a disproof once I find the counterexample. | | | | The core strategy is to establish that A306477 n₀ = 0 by showing that no combination of the four binomial coefficient terms can sum to n₀ across all possible values. I'll need to prove the main combinatorial lemma that for all natural numbers w, x, y, z, the sum w+2 choose 2 + x+3 choose 4 + y+5 choose 6 + z+7 choose 8 never equals n₀, then use this to conclude the function returns zero at that point. | | | | For the computational verification, I'm weighing whether to compute binomial coefficients directly using the polynomial expansion which costs several multiplications and a division per evaluation or find a more efficient approach, possibly through precomputation or reformulating the iteration strategy to reduce the overhead. Instead of computing C8 z repeatedly, I could encode all 119 precomputed values into a single large number using fixed-width bit packing, then extract each value with a shift and mask operation—this trades repeated arithmetic for a single expensive GMP shift on a large integer. | | | | Another angle: restructure the middle loop to iterate over y,z pairs directly, precomputing the distinct B = C6+C8 values and encoding them as a digit-table literal. With ~35,000 pairs, that's about 280KB of literal data in the source file, and each pair lookup requires one deep shift into that large number—expensive per pair but amortized across the inner x loop. | | | | For the innermost work, I can either compute m = W − C4 x per leaf with a few multiplications and a division, or try to avoid that by iterating over candidate root regions instead. Better yet, I could precompute a C4 lookup table with ~2,200 entries at 48 bits each—just 13KB of literal data—and then per leaf, extract the value with a shift and mask operation on that smaller table, which should be much faster than the arithmetic. | | | | The tradeoff is between direct computation a few small multiplies, one GMP division, then filtering versus table lookup shift, mask, subtract, filter . Both seem viable; the direct route is simpler to reason about formally, and I can lean on Mathlib's binomial coefficient lemmas like Nat.choose to express C4 x = x+3 .choose 4 = x x+1 x+2 x+3 /24. Looking for the right lemma about descFactorial and choose — there's something like Nat.descFactorial eq choose mul factorial that relates them directly. For the table-based verification approach, I'd need to prove that each entry matches the binomial coefficient, which means checking 2200 individual cases by computation — each one evaluates choose through the kernel's recursion, which is manageable since it's just a few steps per value. | | | | But actually, I can skip tables entirely and compute the binomial coefficients arithmetically instead — for C4 it's just three multiplications of small numbers plus a division and subtraction, which is about as efficient as a table lookup. I'll prove once that this formula works for all x, then apply it per leaf. Same approach for C6 and C8 with their respective formulas. This eliminates literal tables completely. | | | | The verification loops nest as: outer loop over z up to 119 , then y up to 300 , then x up to 2200 , checking each triple arithmetically. | | | | For each z, y pair, I compute B = C6 y + C8 z , where C8 gets recalculated per pair — that's about 7 multiplications across 35,000 pairs, which is negligible. Then W = n₀ − B, and if B exceeds n₀ I can skip the entire x loop since the sum would exceed the target for all x values. The correctness follows from monotonicity: if B n₀ then the full sum T + C4 + B is always greater than n₀. | | | | In the inner x loop, I compute m = W − C4 x and check if it equals zero, which would mean the sum equals exactly n₀ with T = 0. | | | | For the x-range optimization, instead of computing per-pair bounds, I'm using a global maximum X̄ where C4 x ≤ n₀, then iterating every pair through the full range 0, X̄ . This costs about 77 million operations across all pairs, which is comparable to the current 67 million anyway, so the simpler approach without per-pair bounds is worth it. For each x, I compute c = C4 x , then m = W − c, where natural subtraction truncates to zero if c ≥ W, which correctly marks it as OK. | | | | Now I'm verifying the leaf semantics: when c ≥ W, the sum T + c + B exceeds n₀, so the condition is satisfied. The edge case where B n₀ is already handled at the pair level. For the general case, the leaf is OK if either c ≥ W or the value v = W − c satisfies the condition that 8v + 1 is not a perfect square, with the special case v = 0 meaning c = W already covered. | | | | For the filtering step, the mask test checks whether v mod 7425 falls outside the triangular number image modulo 7425, which guarantees no T can equal v. Per leaf, I'm computing a binomial coefficient x x+1 x+2 x+3 /24 from the leaf index, subtracting from W to get v, taking v modulo 7425, and checking the precomputed bitmask—roughly 11 primitive operations plus tree traversal overhead, totaling around 7.7e7 operations across all leaves. | | | | But the benchmark numbers are concerning: 190 microseconds per leaf with only 6 operations suggests severe CPU contention, possibly from scan33 still running during my fuel-17 benchmark. That would push the total runtime to 8 hours, which is way too slow. I need to re-benchmark in isolation to get accurate measurements. | | | | Once scan99 finishes on an idle machine, the kernel should handle 1-3 microseconds per reduction, giving roughly 30-60 microseconds per leaf. With 77 million leaves, that's 40-77 minutes, which is borderline acceptable. Parallelizing across multiple processes could help, though I'm limited to a single file. A 1-2 hour runtime is manageable if needed. | | | | If performance becomes critical, I could optimize by strip-mining the leaves to handle multiple consecutive values with inlined expression sharing, reducing the division operations required for each product update. | | | | I also need to verify the exact syntax for decide +kernel in Lean 4.27 to ensure it doesn't trigger elaborator evaluation, and confirm whether the fallback approach using Decidable.decide is available. | | | | For proving Bool equalities, I'm considering whether rfl would work directly, but that relies on elaborator normalization which could be slow. The decide +kernel approach is more direct since it calls the kernel reducer, so I'll stick with that for the proof. | | | | Now for the deep-check on non-filtered leaves: I need to use Newton's method to find the integer square root, then verify the bracket inequality to confirm the value isn't a perfect square. The main question is whether Nat.log2 is kernel-accelerated for computing the initial approximation—if not, I can just start Newton from v/2, which converges in about log v iterations. Even with roughly 45 divisions per deep leaf across the million or so deep leaves in the dataset, that's manageable computationally. | | | | Rather than storing certificates for each deep leaf which would bloat the file to ~10MB , I'll implement the Newton loop directly with a fuel parameter and explicit recursion, terminating when the improvement stops improving. This keeps it kernel-friendly and stays well within the linear recursion depth limit. | | | | Now I'm checking the filter pass rate calculation with the Q1 mask... | | | | the image density mod 27 is roughly 37%, mod 11 is about 54%, and mod 25 is around 44%, giving a combined pass rate of about 8.9%. But that would leave 6.8 million deep leaves requiring ~300 reductions each—way too much computation. I need to add a second filter using Q2 = 10829 to cut this down further. | | | | With both masks applied, the pass rates multiply to about 14.5%, reducing the deep rate to just 1.3% and leaving roughly a million leaves to process, which is manageable. The second filter only adds overhead for the survivors of the first filter, averaging about 4 extra operations per leaf. | | | | I also need to verify the correctness of these filters: for each modulus q, if a bit position in the mask is 0, then no value of T w mod q should equal that position. Since T w is periodic with period q, I can check this property systematically. | | | | Verifying the contrapositive: if a leaf has a value v where bit v mod q = 0, then T w can never equal v for any w, because T w mod q would have to equal v mod q, but all computed values of T w' mod q for w' < q have that bit set to 1. | | | | Now I'm encoding the mask values as large integer literals—for the 7425-case that's a 2236-digit number representing which values appear in the image, and similarly for 10829 with 3260 digits. The key insight is that having extra 1-bits in the mask only reduces filtering efficiency but preserves correctness, while missing bits would break soundness, so the decide-lemma confirming all image bits are set is critical. | | | | Starting to assemble the main loop... Now I'm working through how to compute the fuel value per pair using logarithms — specifically, I need to derive X̄ from W using the relationship X̄⁴/24 ≈ W, which gives X̄ ≈ 24W ^{1/4}, so fuel becomes roughly log₂ 24W +3 /4. If I can use a kernel-accelerated log₂ function, I can compute this efficiently and then verify at runtime that the threshold holds by checking c 2^f ≥ W in a single evaluation. | | | | The same approach applies to the y and z loops — I compute the bound B first, and if B exceeds the leaf threshold n₀, I can skip early since the sum will automatically satisfy the constraint. For the z-loop, I need to establish that C8 is monotone in z so that once z exceeds some fixed threshold Z̄, the bound C8 z stays above n₀; I'm working through the calculation to find the right fixed fuel values and bounds — for instance, with n₀ up to 1e13, I'm estimating where the sixth root of the coefficient gives me the threshold around 441. | | | | Now I'm refining the z-tree fuel to 256 and confirming the y-tree fuel at 512, then structuring the two-level tree: first iterate over z to compute C8, and if that's already ≥ n₀ we're done; otherwise, for each z, iterate over y to compute C6 and check if B = C8 + C6 ≥ n₀, falling back to the x-tree only when needed. | | | | Writing the correctness proofs... Working through the remaining cases: when the filter hits with v = W−c, I need to show T w = v is impossible modulo q; for the bracket case, I'm verifying that r² < 8v+1 < r+1 ² prevents 8v+1 from equaling 2w+3 ², which means T ≠ v. The key constraint is ensuring c ≤ W in cases b and c , which follows from the negation of case a giving c < W. Now I'm running into a practical issue with the soundness proofs themselves—the checker uses fuel-based recursion for the trees, which complicates how to structure the inductive arguments. | | | | For the final push, the master theorem combines all the coverage bounds and monotonicity arguments to show that T+C4+C6+C8 ≠ n₀ across the full range, which then proves A306477 n₀ = 0 and completes the disproof. The computational bottleneck is verifying the master statement by decision procedure, so I'm planning to split this into roughly 160 individual lemmas—one for each z value from 0 to 159—where each lemma proves its slice is true, then chunk them to keep individual proof times manageable. | | | | The challenge is combining these 160 Boolean facts back into the master statement without forcing the kernel to recompute everything. The cleaner approach is to make the top-level combination propositional: define a master lemma that says for all z < 256, the slice is okay as a Prop , then prove it by case-matching on the z literal using tactics like interval cases or omega to dispatch each of the 256 cases, pulling in the pre-proved chunk lemmas as needed. Generating the Lean file programmatically... Writing the Lean framework... | | | | I need to verify the decide tactic works in kernel mode and check what axioms it relies on, then start building out the checker definitions and soundness lemmas. I should also compute the image masks with their decidability proofs once the q values are finalized, benchmark the GMP shift operations on the large bitmask, and calculate exact pass rates to optimize Q1 and Q2 selection. Let me check the scan progress while I work through the axiom verification and framework setup. | | While the scan runs, let me develop the Lean framework. First verify decide +kernel exists in this toolchain and check its axioms footprint. | | bash | | | | cd /workspace/leanproject && cat /tmp/dk.lean << 'EOF' | | def f n : Nat : Bool := n n+1 / 2 % 7425 == 1234 | | theorem t1 : f 100 = false := by decide +kernel | | print axioms t1 | | example : 2:Nat + 2 = 4 := by decide +kernel | | EOF | | timeout 60 lake env lean /tmp/dk.lean | | | | bash | | | | cd /tmp && tail -1 scan99.err; python3 << 'EOF' | | exact triangular-image pass rates mod various q, to choose Q1, Q2 | | def tri image q : | | s=set | | for k in range 2 q : | | s.add k k+1 //2 %q | | return s | | from math import prod | | for q in 9,27,81,11,121,25,5,49,7,13,17,19,23,29,31,37 : | | im=tri image q | | print q, len im , round len im /q,4 | | EOF | | | | | | 43 --- TOOL bash --- | | 't1' does not depend on any axioms | | | | | | 43 --- TOOL bash --- | | |S3|=238659134 1.91 GB | | 9 4 0.4444 | | 27 11 0.4074 | | 81 31 0.3827 | | 11 6 0.5455 | | 121 56 0.4628 | | 25 11 0.44 | | 5 3 0.6 | | 49 22 0.449 | | 7 4 0.5714 | | 13 7 0.5385 | | 17 9 0.5294 | | 19 10 0.5263 | | 23 12 0.5217 | | 29 15 0.5172 | | 31 16 0.5161 | | 37 19 0.5135 | | | | | | 44 --- ASSISTANT --- | | The decide +kernel approach is working without needing axioms. I'm comparing pass rates across different modulus options—mod 27 gives 0.4074 versus mod 81 at 0.3827—and evaluating a Q1 configuration with 27·11·25 = 7425 that yields about 0.0978. I'm also checking whether a larger setup with 81·121·25 = 245025 fits within memory constraints before calculating its combined pass rate. | | | | Looking at the three-stage filtering strategy: Q1 at 7425 passes 0.098 of candidates, Q2 with 49·13·17 = 10829 passes another 0.128 combined 1.25% , and Q3 with 19·23·29 = 12673 on survivors adds 0.18% more depth. The per-leaf operation count works out to roughly 12 primitive operations plus tree overhead, so around 19 total reductions per leaf, which should run in 20–40 microseconds each. Scaling to 7.7e7 leaves gives about 38 minutes on a single thread—acceptable if chunked into roughly 32 lemmas. Now I'm checking whether scan99 has produced any "block" lines yet. | | | | Started around 19:55, and it's been over 6 minutes without output from block 1. The calculation suggests block 1 should process about 1.3e11 marks at roughly 1.9e9 marks per second across 16 cores, which would take around 68 seconds, so something seems off with the timing. | | | | Let me check the CPU usage and see if there's contention on atomic operations or maybe a bug like VCAP overflow causing an infinite loop. | | bash | | | | cd /tmp && tail -3 scan99.err; ps aux | grep " s can99" | awk '{print $3,$4,$10}'; top -bn1 | head -15 | tail -8 | | | | | | 44 --- TOOL bash --- | | |S3|=238659134 1.91 GB | | 0.0 0.0 0:00 | | 734 5.0 27:28 | | 0.0 0.0 0:00 | | 0.0 0.0 0:00 | | 1538 root 20 0 7692820 6.3g 1992 R 931.2 5.1 27:29.92 scan99 | | 1 root 20 0 2524 1520 1412 S 0.0 0.0 0:00.10 tail | | 171 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 bash | | 292 root 20 0 0 0 0 Z 0.0 0.0 4:47.53 python3 | | 615 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 bash | | 854 root 20 0 0 0 0 Z 0.0 0.0 0:00.55 lake | | 900 root 20 0 0 0 0 Z 0.0 0.0 4:03.34 lean | | 918 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 pkill | | | | | | 45 --- ASSISTANT --- | | The CPU is running at 931% with 27 minutes of processing time so far, but no blocks have completed yet—something's taking longer than expected. I'm breaking down the memory usage: S3 is using 1.9GB, bits 0.5GB, and the vector buffers account for the remaining 4.3GB across 16 threads, which matches the total 6.3GB observed. Now I'm trying to figure out what's causing the slowdown—possibly something with the scheduling or how the work is being distributed across threads. Most of the s-values are larger than the threshold, so they should skip quickly, but I'm noticing that only 9.3 cores are busy, which suggests some threads finished while others are still working. I'm wondering if there's a load balancing issue or if one particular s-chunk is taking disproportionately long to process, especially for smaller s-values where the iteration count could be much higher. The chunking strategy with 8192 chunks looks reasonable for the parallelization. Now I'm setting up the Lean framework for the formal verification — I'll create the spec file with the problem definition, the counterexample value n₀, and the mask constants that the script computed. | | | | I need to implement a generic balanced tree combinator for checking properties across bounded ranges, since a linear recursion would be too deep for values up to 12673. This will let me efficiently verify that the triangular residues match the expected bit patterns in each mask. | | | | Now I'm proving the soundness of this balanced forall function by induction on the tree depth, showing that if it returns true for a range, then the property holds for every element in that range. The base case is straightforward since a single element range just checks the property directly, and the recursive case combines results from two halves using the fact that shifting left by f+1 is equivalent to doubling the shift by f. | | | | I'm considering using 2 ^ f instead of bit shifts for clarity, and I need the lemma that 2^ f+1 equals 2^f + 2^f. The kernel can handle the generic higher-order predicate passed as a closure without issues, and the soundness proof only needs to be written once. Now I'm moving on to write the main checker function. | | | | Defining the combinatorial functions for the triangular and binomial coefficients, then implementing a bit-testing utility to check specific bits in a mask, and finally setting up the core predicate that checks whether a number m is not representable as a positive triangular number by testing against a precomputed mask. | | | | I'm reconsidering the approach to use early-exit logic with nested conditionals rather than pattern matching, since structural recursion compiles inefficiently. I'm switching to explicit Nat.rec to have direct control over kernel unfolding behavior. | | | | Writing recursive definitions... | | | | For the primality check, I need to compute the integer square root using Newton's method with a fuel parameter, then verify that the square of the result and its successor bracket the input value. The seed can start at v/2 + 1, and 50 iterations should be sufficient since convergence is logarithmic in the input size. Using a bit-length-based seed like 2^ ⌈bits/2⌉ gives a better starting point that's guaranteed above the square root, and Newton's method converges monotonically downward from there, which is cleaner than trying to optimize the seed calculation itself. | | | | Now I need to verify the soundness of the notSquare check: if it returns true, then for any integer j, either j ≤ r so j² ≤ r² < v or j ≥ r+1 so j² ≥ r+1 ² v , meaning no perfect square equals v. | | | | For the triangular number case, I'm showing that 8m+1 = 2w+3 ² using the fact that w+2 w+1 is always even, so I can factor out the 8 cleanly and verify the equality by ring normalization. This contradicts notSquare 8m+1 returning true, which is what we need. | | | | For the filter soundness, I need to establish a lemma showing that for each modulus q, the mask bit operation on the triangular residue holds—this reduces to checking the property on the reduced form w % q. | | | | Now I'm working through why t2 w mod q depends only on w mod q when q is odd. The key insight is that since 2 is invertible modulo any odd q, I can multiply both sides by 2 and work with the polynomial w+2 w+1 directly. By substituting w = qd + r and expanding, the qd terms vanish modulo q, leaving only the r+2 r+1 part. Rather than dividing by 2 directly in natural numbers, I'll use the fact that 2a ≡ 2b mod q implies a ≡ b mod q when gcd 2,q = 1, then cancel the factor of 2 using coprimality. Working in ZMod q makes this cleanest since 2 becomes a unit there. Looking for the right lemma about when 2 is a unit in ZMod q — I think it's something like ZMod.isUnit iff coprime that characterizes units by coprimality, which would let me cancel the factor of 2 from both sides. | | | | Then for the maskBit part, I need to connect the ZMod equality back to natural number modular arithmetic using the fact that casting preserves congruences — something like ZMod.natCast eq natCast iff should give me that two natural numbers are equal in ZMod q exactly when they're congruent modulo q. | | | | Actually, there's a simpler path avoiding ZMod altogether: I can expand t2 w directly where w = qd + r, which gives me qd+r+2 qd+r+1 /2, and then factor this as r+2 r+1 /2 plus qd qd+2r+3 /2 — the key is checking whether that second term is always an integer, which depends on the parity of d and q. | | | | When d is odd and q is odd, qd is odd, so qd+2r+3 is even, making the product divisible by 2. When d is even, the divisibility works out too. So t2 w ≡ t2 r mod q always holds, which means I can work directly with remainders rather than using ZMod. Though in Lean this gets messy with natural number division, so the ZMod approach might be cleaner after all. Or I could try filtering on the 8m+1 masks instead, where the image becomes odd squares modulo q. | | | | For the mask lemma, I need to show that squaring any value 2w+3 ² mod q gives a bit of 1. The key insight is that squaring is periodic modulo q by the standard Nat.pow mod and Nat.mul mod lemmas—no parity tricks needed. As w ranges over 0,q , the values 2w+3 mod q cover all residues, so I just need to verify that for any residue u, the bit of u² mod q is true. Verifying the mask lemma by checking all residues up to the modulus, then using that to prove soundness: if a bit test fails for any of the three moduli or the bracket check, then no integer j can satisfy j² = v. This unified approach rules out all possibilities, including j = 2w+3, which leads to a contradiction when m ≥ 1. | | | | Now I'm structuring the leaf function to handle the edge case where c ≥ W separately—when m = 0, v equals 1 which is a perfect square, so the function returns true immediately. For the remaining cases where c < W and m ≥ 1, I'm computing v and applying the mask tests. | | | | Defining the leaf function... I'm working through the case where c < W, showing that if t2 w + c equals W, then v becomes a perfect square, which contradicts the mask and bracket checks that ensure v isn't a perfect square. For the x-tree, I need to verify that the leafX predicate covers all values beyond the threshold by confirming c4 at the boundary is at least W. The Python simulation will verify the formula works before generating the file, catching any underestimation bugs upfront. Computing c4 2^fx is feasible even for large values. I'm settling on the per-pair log2 approach for fx rather than a fixed value, then at the y-level I'll compute c6 from the y range and combine it with c8 to determine B. I'm settling on a fixed fy value based on the maximum y-range, which avoids recomputing it per z and keeps the overhead minimal—the early exits in leafY are cheap enough that even wasted leaves across all z values amount to negligible overhead. The same approach applies to the z-level with a fixed fz, building a tree structure over z. | | | | For the x-loop, I can apply the same strategy: use a fixed fx derived from the maximum x-range across all pairs, then rely on cheap early-out leaves that check bounds before diving deeper—the waste from pairs that don't reach the x-tree is acceptable given the cost savings. | | | | But I can do better by deriving fx directly from W itself. Since X scales roughly as 24W ^0.25, I can compute fx = log₂ 24W /4 + 1, which ensures that 2^fx is large enough to cover all pairs reaching that node—this avoids the per-pair overhead while keeping the bound tight. | | | | For the z-level, I'm fixing fz = 8 to handle up to about 3.5×10¹³ nodes, which gives me plenty of headroom for the binomial coefficient bound. | | | | For the y-level, I'm setting fy = 9 with a similar calculation using the binomial coefficient c6 512 , which covers n₀ up to roughly 2.6×10¹³. | | | | Now I'm splitting the z-tree into 16 chunks of 16 z-values each and verifying that the leaf condition holds for each chunk. | | | | I'm analyzing how the kernel distributes across chunks—the early z-values carry the heaviest load around 35-40% of all triples , so I need to balance the theorem generation either by grouping small z-values individually and combining larger ones, or generating one theorem per z-value to keep each kernel manageable at 1-3 minutes per theorem. Now I'm thinking about how to combine these per-z theorems into a master proof. I could use interval cases to dispatch on the z literal across all 256 branches, applying the corresponding theorem to each—it's heavy with elaboration overhead but should work as a one-time cost. The alternative of bundling the theorems into a single value doesn't help without recomputing, so the case-splitting approach seems most practical despite the computational weight. Generating proof theorems... I could try chunking the theorems differently—maybe 32 chunks of 8 with fuel 3 for finer error isolation, then combining those 32 results back up through 31 steps to prove the full property. This gives me composite theorems at each level that I can stack together. | | | | For the combining steps, I'm working with the allB succ rewrite to handle the conjunction of two subtrees—so I need to prove x && y = true by showing both sides are true, then use Bool.and eq true to combine them. The tricky part is normalizing the arithmetic in the goal after rewriting, like converting 0 + 2^4 to 16 , which I can handle with Nat.zero add or norm num . | | | | Now I'm realizing the rewrite itself might be more subtle—the lemma allB p f+1 a needs to unify with the goal where the fuel is literally 5 , so the unifier has to match 5 =?= ?f + 1 through definitional equality, which might not work directly with the syntactic form. | | | | For the bridge to proving A306477 = 0 , I'm unfolding the definition and applying a sum-to-zero tactic by showing that each term in the nested sum over the four-dimensional range fails the equality check—the binomial coefficient combinations never equal the target value. | | | | Now I'm connecting the binomial coefficients to their polynomial forms using Mathlib lemmas. For w+2 .choose 2 , I can use the standard formula to get w+2 w+1 /2 . For the larger binomial coefficients like x+3 .choose 4 , I'm leveraging the descending factorial representation: x+3 .descFactorial 4 / 24 , which expands to the product x+3 x+2 x+1 x divided by 4 . | | | | The key insight is that these products are commutative—the order doesn't matter—so I can rearrange them using ring nf or ac rfl to match whatever form I need. The factorials themselves are just concrete computations: 4 = 24 , 6 = 720 , 8 = 40320 , all verifiable by reflexivity. | | | | Finally, I'm proving the disproof of the conjecture by showing that A306477 n0 equals zero for some specific n0 , which contradicts the claim that all values are positive. | | | | Now I need to nail down the naming convention—the theorem should be called oeis 306477 conjecture 1.disproof and I should delete the original conjecture statement. After that, the remaining work is finding the actual counterexample n0 and handling the engineering side: checking whether the kernel evaluation is efficient enough and measuring performance, though the machine is currently busy with other tasks. I can still work on the correctness proofs in the meantime since those are lighter on resources. | | | | Before diving in, I should verify that importing FormalConjectures.Util.ProblemImports works and check whether Mathlib is prebuilt—I know plain file elaboration worked before with lake env lean , so I'll test the import speed to see how long it takes to load the oleans and confirm that FormalConjectures builds are properly cached. | | I've confirmed that decide +kernel works with zero axioms and identified that filter masks should be squares mod q applied to v=8m+1. Now I'll verify the Mathlib import and start building the Lean framework file. | | bash | | | | cd /workspace/leanproject && echo 'import FormalConjectures.Util.ProblemImports | | check Nat.choose two right | | check Nat.choose eq descFactorial div factorial | | check @Nat.descFactorial | | example n:ℕ : n.descFactorial 4 = n-3 n-2 n-1 n 1 := by simp Nat.descFactorial | | ' /tmp/imp.lean && time timeout 280 lake env lean /tmp/imp.lean | | | | | | 45 --- TOOL bash --- | | | | real 0m13.541s | | user 0m4.856s | | sys 0m1.847s | | | | Nat.choose two right n : ℕ : n.choose 2 = n n - 1 / 2 | | Nat.choose eq descFactorial div factorial n k : ℕ : n.choose k = n.descFactorial k / k.factorial | | Nat.descFactorial : ℕ → ℕ → ℕ | | | | | | 46 --- ASSISTANT --- | | The imports are loading successfully and the basic lemmas are in place. Now I need to set up the main framework file with all the soundness proofs, starting with a placeholder value for n₀ that lets me develop the generic lemmas independently before committing to the actual literal value in the final generated file. | | | | I'm laying out the structure: defining allB and its soundness, then the t2 and c4-related definitions with monotonicity lemmas, followed by sqrtAux and the bracket checking logic. For the square-mask verification, I'm parameterizing by q and mask with a generic predicate that checks whether the mask covers all residues correctly — the key insight is that even though the tree evaluation range 0, 2^fq extends beyond 0, q , the extra values automatically satisfy the mask condition since they have the same residues as their counterparts in 0, q , so I can prove this using Nat.mul mod to show j j % q equals j % q j % q % q. Then I'll add the leafX soundness proof, the xtree construction with per-pair runtime analysis, and leafY. | | | | Now I'm completing the tree structure with leafZ and ztree, then building the master lemma parameterized on n0 that combines the ztree verification with the bound constraint to prove no solution exists — this stays fully generic so the generated file can instantiate it with concrete literals and let the kernel verify the chunk facts cheaply. From there I extract the A306477 eq zero result, and I'm fixing the three mask constants q1 7425, q2 10829, q3 12673 with their sqAll facts verified by decision procedure. | | | | For the performance benchmark, I need to figure out how to time the checker meaningfully — running it on a small n0 where it returns false gives incomplete measurements due to short-circuiting, so I'm considering whether to use a known impossible n0 value that forces the checker to return true, or perhaps temporarily invert the bracket semantics to benchmark with modified masks, though the simplest approach is just picking a specific n0 and measuring the full run. | | | | Actually, a cleaner solution: I can define a modified leaf function that always returns true by using a logical OR with true, which forces the full computation to happen before the short-circuit takes effect — this gives me a complete timing measurement of the work. Now I need to set up the benchmarking variant, monitor scan99, and start writing the Checker.lean file. | | Import works. Now let me write the generic checker framework with all soundness proofs parameterized by n0 , so it's ready the moment the scan finds a counterexample . | | bash | | | | cd /tmp && tail -1 scan99.err; mkdir -p /workspace/leanproject/Dev | | | | | | 46 --- TOOL bash --- | | block 2/24 done marks=149884355180 zeros=0 | | | | | | 47 --- ASSISTANT --- | | I've completed 2 out of 24 blocks so far, each containing about 1.5e11 marks with no zeros appearing yet in the range I've checked. At this pace of 2 blocks every 20 minutes, the full search should take around 4 hours, which is slower than ideal but manageable. I'll decide whether to extend the search beyond 1e13 once I see how the rest progresses. | | | | I'm expecting to find maybe 1-5 zeros in the mod-99 class across the full range, though it's highly uncertain. If I find one early, I could potentially stop, but I'll let it run through to collect all results. While the search continues, I'm writing the Dev/Checker.lean module with hot-path functions defined directly using low-level Nat operations like Nat.mul, Nat.mod, and Nat.beq to avoid the overhead of typeclass instance unfolding during kernel reduction. The key function shapes use conditional logic to check divisibility and bit operations efficiently. | | | | Continuing the hot function definition... I'm wondering whether cond unfolds to Bool.casesOn during kernel reduction or if I should use Bool.rec directly to be safe, or maybe just use an if-then-else expression instead and test the performance implications. | | | | For Bool.or , the core library's macro-inline definition should expand to nested cond calls, which is fine for my purposes. Now I'm working on allB , a closure-generic function that uses recursion over natural numbers with a motive to accumulate boolean results across a fuel-based traversal. | | | | The key insight for Bool.and is that while it takes two arguments, the cond implementation makes it lazy in the second argument—if the first is false, it short-circuits to false without evaluating the second. For the soundness proof of allB , I need to show that if it returns true for a given fuel and starting point, then the predicate holds for all indices in the range. The base case is straightforward since 2^0 = 1 leaves only one index to check, and the inductive step splits the range in half using the recursive structure. | | | | For the definitional equality check, rfl works directly because Nat.rec reduces on the successor constructor, so the recursive call unfolds properly. Then I apply Bool.and eq true to decompose the conjunction, case-split on whether the index falls in the first or second half of the range, and use arithmetic lemmas like pow succ and two mul with omega to verify the bounds. | | | | Now I'm shifting to computing quadratic residues modulo composite numbers using the Chinese Remainder Theorem—breaking down Q1 = 7425 into its prime power factors and computing which squares are possible modulo each factor. The pass rate for v-random-mod-q matches the square count I computed earlier—for q=27 there are 11 squares giving 11/27 ≈ 0.4074, which checks out. Now I need to compute the actual masks and image sizes using Python, then write out the Lean file with concrete mask literals and work through the sqMask lemmas. I should also figure out the optimal choice of Q1, Q2, Q3. | | | | Looking at candidate combinations: 7425 27·25·11 gives a rejection rate of about 0.0978, 10829 49·13·17 gives 0.128, and 12673 19·23·29 gives 0.142. Adding a fourth modulus like 31·37·5 would only marginally improve things, so three masks should be sufficient. The combined deep rejection rate across all three is roughly 0.00178. For the Lean decide-lemmas I need to verify that 2^13 = 8192 is large enough to handle the largest mask value of 7425. | | | | Now I'm confirming the bit-width requirements: 2^14 = 16384 covers both 10829 and 12673, so fq2 and fq3 both need 14 bits. I also need to verify that the tree evaluation stays within bounds when computing u u % q, which checks out since 2^f ≥ q ensures we don't overflow. Next I'll write the Python mask generator to output the Lean literals to a file, then move on to implementing Checker.lean. | | Block 2 of 24 is complete with about 4 hours remaining for the full scan. I'll now compute the square-residue masks and write the checker framework. | | bash | | | | cd /tmp && python3 << 'EOF' | | qs = 7425, 10829, 12673 | | for q in qs: | | im = set j j % q for j in range q | | mask = 0 | | for u in im: mask |= 1 << u | | print f"q={q} |image|={len im } rate={len im /q:.4f} digits={len str mask }" | | with open f"mask {q}.txt","w" as f: f.write str mask | | EOF | | ls -la mask .txt | | | | | | 47 --- TOOL bash --- | | q=7425 |image|=726 rate=0.0978 digits=2232 | | q=10829 |image|=1386 rate=0.1280 digits=3256 | | q=12673 |image|=1800 rate=0.1420 digits=3809 | | -rw-r--r--. 1 root root 3256 Aug 2 20:04 mask 10829.txt | | -rw-r--r--. 1 root root 3809 Aug 2 20:04 mask 12673.txt | | -rw-r--r--. 1 root root 2232 Aug 2 20:04 mask 7425.txt | | | | | | 48 --- ASSISTANT --- | | I'm starting to write the Lean checker file with careful attention to kernel-friendly definitions, particularly using Nat.rec with proper motive annotations and structuring recursive functions like allB appropriately. I'll need to establish several soundness lemmas to verify the checker's correctness, beginning with the foundational ones. | | | | Now I'm working through the power notation carefully—deciding whether to use Nat.pow 2 f explicitly in definitions or rely on 2^f notation, and ensuring they're definitionally equal or connected via simp lemmas so the proofs work smoothly without elaboration issues. | | | | I'm drafting the full file with the soundness statement chain and the bridge lemma connecting to A306477, then defining the generic theorem with helper functions like t2 for binomial coefficients and p4 for multiplication. | | | | Now I'm setting up the core definitions for c4 , c6 , c8 as divided products, along with the foundational lemma that t2 is always at least one by showing the product w+2 w+1 is at least two. | | | | I'm proving that 8 t2 w + 1 equals 2 w+3 ^2 by leveraging the fact that consecutive integers produce an even product, then using properties of division and multiplication to simplify 8 w+2 w+1 /2 down to 4 w+2 w+1 , which rings out to the desired form. | | | | For the monotonicity proofs of c4 , c6 , and c8 , I'm using gcongr to handle the chains of inequalities through multiplication and division in the naturals—it should work directly on these operations without needing explicit lemmas. | | | | Now I'm defining the maskBit function... | | | | Defining the square-checking logic... Now I'm unfolding the leafX condition and doing case analysis on whether W is at most c4 x. When that's true, the sum t2 w + c4 x is at least 1 + W, which is strictly greater than W. When it's false, I need to show that if t2 w + c4 x equals W, then v = 2w+3 ² is a perfect square, and the nested conditions in rest should extract a contradiction either from the mask bits or from the bracket check. | | | | For the proof structure, I'm considering whether to use rcases on the boolean condition values with cases hb : Nat.ble W c , then simplify with the unfolded definition. Since leafX is built with many let bindings, I need to be careful about how to structure the proof—either refactor leafX as a chain of named definitions or rewrite it using if-then-else on propositions with decidable instances, though that adds extra kernel unfolding steps. | | | | I'm settling on using Bool and cond for simplicity: after cases hb : Nat.ble W c , a simp leafX, hb should reduce the conditional properly since the standard simp lemmas for Bool.cond true and Bool.cond false exist, and simp's default zeta reduction will handle the let-bindings when unfolding the definition. | | | | Now I'm moving on to define the nested filter part. Now I'm connecting the soundness proof by using the mask lemmas to show that all three bit checks pass when v is a perfect square, which forces sqTest to return true and leads to the contradiction. Then I'm applying this same reasoning to leafX sound by substituting the specific values from the tree structure, and starting to define the overall tree validation function. Now I'm defining a leaf function that takes a parameter for the target value and checks whether a sum involving multiple components exceeds that target, with a soundness proof showing that when the function returns true, the sum is guaranteed to be larger than the target. Now I'm establishing the top-level constraint that no combination of these four summands can equal N, then connecting this back to the sequence definition where A306477 equals zero when this condition holds. I'm translating the combinatorial formula for choosing two elements into the formal representation needed to complete the proof. I'm working through the definition of descending factorial: it's defined recursively where descFactorial n 0 = 1 and descFactorial n k+1 = n−k descFactorial n k. For n = x+3, this gives me x x+1 x+2 x+3 , and I can verify both associativity patterns are equivalent using the ring tactic since they're just products of the same factors. | | | | Now I'm connecting this to binomial coefficients: x+3 .choose 4 equals p4 x divided by 24, which I can establish through the choose eq descFactorial div factorial lemma combined with factorial normalization 4 = 24 reduces by reflexivity . I'll apply the same approach for the larger binomial coefficients in the sequence, then handle the main summation by rewriting the condition from A306477 into the form needed for the proof, using nested Finset.sum eq zero with conditional logic. | | | | For the final assembly, I'm generating per-element theorems that each leaf satisfies the condition, then combining them level by level using allB rewrites to build up to the complete proof—though the number of individual chunk theorems grows exponentially with the parameter size. The issue is that a + 2^ ℓ-1 remains unevaluated when I need to match it against the child theorem's literal value like allB p ℓ-1 192 . I'm planning to use norm num to normalize the arithmetic expression into a concrete number, which should leave the allB application untouched since there are no simplification lemmas for it, then rewrite with the child theorems to reduce both conjuncts to true and finish with reflexivity. | | | | Alternatively, I could bypass the allB machinery entirely by creating a generic master lemma that takes a hypothesis in propositional form—something like proving that for all z < ZB , the leaf value at position z equals true . Then for the 256-case, I'd generate a term that pattern-matches on z across all 256 literal values, with a catchall clause that uses omega to derive a contradiction for any z ≥ 256 , which elaborates into nested case analysis. | | | | Or even simpler: make the top z-level part of the kernel computation itself by chunking the theorems into z-subtrees—proving allB leafZ N FY 4 16 i = true for each chunk i from 0 to 15, giving me 16 separate chunk theorems that distribute the work more evenly, with the heaviest chunk handling roughly half the total computation but still manageable in a single kernel declaration. | | | | Then I'd combine those 16 chunks back up through 4 levels of allB succ rewrites using 15 combining theorems to reach the master proof. For even finer balance, I could split the z values more granularly—proving z=0..31 individually, then grouping larger ranges 32..63 , 64..127 , 128..255 with increasing fuel levels, which gives me around 35 chunk theorems plus 36 combining theorems that a generation script can handle automatically. | | | | I also need to verify the FY check lemma that bounds the result. | | | | The ytreeOK evaluation happens cheaply per z-leaf, and the partial application leafZ N FY : Nat → Bool works correctly. For the Nat.log2 acceleration—even though there are roughly 35,000 calls on numbers up to 44 bits, the unaccelerated version with 44 unfolds takes only about 9 million steps total, which is acceptable. Newton's method with fuel 64 is similarly fine, and the bracket checks around 140K calls should be manageable. | | | | The allB closure with p = leafX W is shared as a fixed subterm during reduction, so there's no redundant recreation per node. Now I need to write the dev file, including a small copy of the A306477 definition and a final disproof shape with a placeholder N to ensure everything typechecks generically. | | | | Setting up the generic section... | | Now writing the full generic checker + soundness framework: | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | | | /- Kernel-friendly checker that a given N has no representation | | N = T w + C4 x + C6 y + C8 z | | where T w = w+2 w+1 /2, C4 x = x x+1 x+2 x+3 /24, | | C6 y = y⋯ y+5 /720, C8 z = z⋯ z+7 /40320. -/ | | | | namespace D | | | | /-- balanced bounded forall: allB p f a = true iff p i for all i ∈ a, a + 2^f . -/ | | def allB p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | p | | fun f ih a = ih a .and ih Nat.add a Nat.pow 2 f | | fuel | | | | theorem allB zero p : Nat → Bool a : Nat : allB p 0 a = p a := rfl | | | | theorem allB succ p : Nat → Bool f a : Nat : | | allB p f+1 a = allB p f a .and allB p f a + 2^f := rfl | | | | theorem allB sound {p : Nat → Bool} : ∀ f : Nat a : Nat , allB p f a = true → | | ∀ i, a ≤ i → i < a + 2^f → p i = true := by | | intro f | | induction f with | | | zero = | | intro a h i h1 h2 | | have : i = a := by omega | | simpa this using h | | | succ f ih = | | intro a h i h1 h2 | | rw allB succ, Bool.and eq true at h | | rcases Nat.lt or ge i a + 2^f with hlt | hge | | · exact ih a h.1 i h1 hlt | | · refine ih a + 2^f h.2 i hge ? | | have : a + 2^ f+1 = a + 2^f + 2^f := by | | rw Nat.pow succ ; omega | | omega | | | | /- arithmetic pieces -/ | | | | def t2 w : Nat : Nat := Nat.div Nat.mul Nat.add w 2 Nat.add w 1 2 | | def p4 x : Nat : Nat := Nat.mul Nat.mul Nat.mul x Nat.add x 1 Nat.add x 2 Nat.add x 3 | | def c4 x : Nat : Nat := Nat.div p4 x 24 | | def p6 y : Nat : Nat := | | Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul y Nat.add y 1 Nat.add y 2 Nat.add y 3 Nat.add y 4 Nat.add y 5 | | def c6 y : Nat : Nat := Nat.div p6 y 720 | | def p8 z : Nat : Nat := | | Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul z Nat.add z 1 Nat.add z 2 Nat.add z 3 Nat.add z 4 Nat.add z 5 Nat.add z 6 Nat.add z 7 | | def c8 z : Nat : Nat := Nat.div p8 z 40320 | | | | theorem t2 ge one w : Nat : 1 ≤ t2 w := by | | have h : Nat.mul Nat.add w 2 Nat.add w 1 ≥ 2 := by | | have := Nat.mul le mul Nat.le add left 2 w Nat.le add left 1 w | | simpa Nat.mul comm using Nat.mul le mul show 2 ≤ w + 2 by omega show 1 ≤ w + 1 by omega | | show 1 ≤ Nat.div 2 | | omega | | | | theorem eight t2 w : Nat : 8 t2 w + 1 = 2 w+3 2 w+3 := by | | have h2 : 2 ∣ w+2 w+1 := by | | rcases Nat.even or odd w with he | ho | | · obtain ⟨k, hk⟩ := he | | exact ⟨ k+1 w+1 , by subst hk; ring⟩ | | · obtain ⟨k, hk⟩ := ho | | exact ⟨ w+2 k+1 , by subst hk; ring⟩ | | obtain ⟨k, hk⟩ := h2 | | have : t2 w = k := by | | show Nat.div w+2 w+1 2 = k | | omega | | rw this | | nlinarith hk | | | | theorem c4 mono {x x' : Nat} h : x ≤ x' : c4 x ≤ c4 x' := by | | apply Nat.div le div right | | unfold p4 | | simp only Nat.mul eq, Nat.add eq | | gcongr <; omega | | | | theorem c6 mono {y y' : Nat} h : y ≤ y' : c6 y ≤ c6 y' := by | | apply Nat.div le div right | | unfold p6 | | gcongr <; omega | | | | theorem c8 mono {z z' : Nat} h : z ≤ z' : c8 z ≤ c8 z' := by | | apply Nat.div le div right | | unfold p8 | | gcongr <; omega | | | | /- square filters -/ | | | | def maskBit mask u : Nat : Bool := Nat.beq Nat.land Nat.shiftRight mask u 1 1 | | | | def sqAll q mask : Nat fq : Nat : Bool := | | allB fun u = maskBit mask Nat.mod Nat.mul u u q fq 0 | | | | theorem sqAll sound {q mask fq : Nat} hq : 0 < q hle : q ≤ 2^fq | | h : sqAll q mask fq = true : ∀ j : Nat, maskBit mask j j % q = true := by | | intro j | | have hj : j % q < q := Nat.mod lt hq | | have := allB sound fq 0 h j % q Nat.zero le by omega | | simpa Nat.mul mod j j q using this | | | | /-- Newton iteration for isqrt; result is just a candidate, soundness never relies on it. -/ | | def newtonAux v : Nat : Nat → Nat → Nat := | | fun fuel = Nat.rec motive := fun = Nat → Nat | | fun g = g | | fun ih g = | | let g2 := Nat.div Nat.add g Nat.div v g 2 | | cond Nat.blt g2 g ih g2 g | | fuel | | | | def newton v : Nat : Nat := | | newtonAux v 64 Nat.pow 2 Nat.add Nat.div Nat.log2 v 2 1 | | | | /-- check r r < v < r+1 r+1 for r = newton v ; implies v is not a square. -/ | | def bracketOK v : Nat : Bool := | | let r := newton v | | Nat.blt Nat.mul r r v .and Nat.blt v Nat.mul Nat.add r 1 Nat.add r 1 | | | | theorem bracketOK sound {v : Nat} h : bracketOK v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | rw bracketOK, Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | simp only Nat.blt eq, Nat.mul eq, Nat.add eq at h1 h2 | | set r := newton v with hr | | rcases Nat.le or lt j r with hle | hlt | | · have : j j ≤ r r := Nat.mul le mul hle hle | | omega | | · have : r+1 r+1 ≤ j j := Nat.mul le mul hlt hlt | | omega | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | head -40 | | | | | | 48 --- TOOL bash --- | | Dev/Checker.lean:40:0: warning: This file has more than one module docstring /- ... -/ . Only the first one is treated as module documentation; convert additional ones to regular comments /- ... -/ . | | | | Note: This linter can be disabled with set option linter.style.moduleDocstring false | | Dev/Checker.lean:57:2: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | a ≥ 2 | | where | | a := ↑ w.add 2 .mul w.add 1 | | Dev/Checker.lean:69:4: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | b ≥ 0 | | a ≥ 0 | | a - b ≥ 1 | | where | | a := ↑k | | b := ↑ w + 2 w + 1 .div 2 | | Dev/Checker.lean:77:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/Checker.lean:77:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/Checker.lean:82:2: error: gcongr did not make progress | | Dev/Checker.lean:87:2: error: gcongr did not make progress | | Dev/Checker.lean:89:0: warning: This file has more than one module docstring /- ... -/ . Only the first one is treated as module documentation; convert additional ones to regular comments /- ... -/ . | | | | Note: This linter can be disabled with set option linter.style.moduleDocstring false | | Dev/Checker.lean:101:2: error: Tactic simp failed with a nested error: | | maximum recursion depth has been reached | | use set option maxRecDepth <num to increase limit | | use set option diagnostics true to get diagnostic information | | Dev/Checker.lean:126:9: error lean.unknownIdentifier : Unknown constant Nat.le or lt | | Dev/Checker.lean:126:31: error: Tactic rcases failed: x✝ : ?m.72 is not an inductive datatype | | | | | | 49 --- ASSISTANT --- | | I'm noticing that omega doesn't handle Nat.mul and Nat.div as transparent operations—it seems to recognize HDiv.hDiv a 2 and Nat.div but treats compound expressions like w.add 2 .mul w.add 1 as atomic terms rather than expanding them, which is blocking the solver from making progress. | | | | The real issue is that using standard notation , / , + instead of dot notation unfolds through multiple instance layers HMul → Mul.mul → instMulNat → Nat.mul , adding ~80 extra delta steps per leaf and potentially causing 2-4× slowdown in hot definitions. So I should keep the Nat. form in the actual definitions but write mirror lemmas using standard notation that are defeq by reflexivity, then prove everything about the cleaner notation version. | | | | For the t2 ge one proof, I need to rewrite it cleanly using t2 def to unfold the definition, then apply Nat.mul le mul to establish the bounds and use Nat.le div iff mul le to handle the division constraint properly. | | | | The key insight is that omega actually understands division and modulo by literal constants, so after rewriting to notation form it should work fine — the problem was that omega couldn't reason about the Nat.div form directly, but once I convert to the standard notation version it becomes tractable. | | | | For the polynomial definitions like p4 and c4 , I should define them with the standard left-associative multiplication notation and use @ local rfl lemmas so the definitions unfold cleanly. Then gcongr should handle the inequality chains on natural numbers using Nat.mul le mul' automatically. I also need to use le or lt for the disjunction name and handle the bitwise operations separately. | | | | Now I'm looking at the comparison lemmas— Nat.blt eq and Nat.beq have simp lemmas like Nat.beq eq... that should simplify cleanly. Let me rewrite the failing proofs to use these lemmas directly. | | I've identified that the Nat.mul/div spelling is confusing omega and gcongr , and I'll fix this by adding rfl bridge lemmas to standard notation and cleaning up the proofs. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | import re | | src = open 'Dev/Checker.lean' .read | | | | insert def-notation bridge lemmas after c8 def and fix proofs | | old t2 = '''theorem t2 ge one w : Nat : 1 ≤ t2 w := by | | have h : Nat.mul Nat.add w 2 Nat.add w 1 ≥ 2 := by | | have := Nat.mul le mul Nat.le add left 2 w Nat.le add left 1 w | | simpa Nat.mul comm using Nat.mul le mul show 2 ≤ w + 2 by omega show 1 ≤ w + 1 by omega | | show 1 ≤ Nat.div 2 | | omega''' | | new t2 = '''theorem t2 def w : Nat : t2 w = w+2 w+1 /2 := rfl | | theorem p4 def x : Nat : p4 x = x x+1 x+2 x+3 := rfl | | theorem c4 def x : Nat : c4 x = p4 x / 24 := rfl | | theorem p6 def y : Nat : p6 y = y y+1 y+2 y+3 y+4 y+5 := rfl | | theorem c6 def y : Nat : c6 y = p6 y / 720 := rfl | | theorem p8 def z : Nat : p8 z = z z+1 z+2 z+3 z+4 z+5 z+6 z+7 := rfl | | theorem c8 def z : Nat : c8 z = p8 z / 40320 := rfl | | | | theorem t2 ge one w : Nat : 1 ≤ t2 w := by | | rw t2 def | | have h : 2 ≤ w+2 w+1 := Nat.mul le mul by omega by omega | | omega''' | | assert old t2 in src | | src = src.replace old t2, new t2 | | | | old e = ''' obtain ⟨k, hk⟩ := h2 | | have : t2 w = k := by | | show Nat.div w+2 w+1 2 = k | | omega | | rw this | | nlinarith hk ''' | | new e = ''' obtain ⟨k, hk⟩ := h2 | | have ht : t2 w = k := by rw t2 def, hk ; omega | | rw ht | | nlinarith hk ''' | | assert old e in src | | src = src.replace old e, new e | | | | old c4 = '''theorem c4 mono {x x' : Nat} h : x ≤ x' : c4 x ≤ c4 x' := by | | apply Nat.div le div right | | unfold p4 | | simp only Nat.mul eq, Nat.add eq | | gcongr <; omega''' | | new c4 = '''theorem c4 mono {x x' : Nat} h : x ≤ x' : c4 x ≤ c4 x' := by | | rw c4 def, c4 def | | apply Nat.div le div right | | rw p4 def, p4 def | | gcongr <; omega''' | | assert old c4 in src | | src = src.replace old c4, new c4 | | | | old c6 = '''theorem c6 mono {y y' : Nat} h : y ≤ y' : c6 y ≤ c6 y' := by | | apply Nat.div le div right | | unfold p6 | | gcongr <; omega''' | | new c6 = '''theorem c6 mono {y y' : Nat} h : y ≤ y' : c6 y ≤ c6 y' := by | | rw c6 def, c6 def | | apply Nat.div le div right | | rw p6 def, p6 def | | gcongr <; omega''' | | assert old c6 in src | | src = src.replace old c6, new c6 | | | | old c8 = '''theorem c8 mono {z z' : Nat} h : z ≤ z' : c8 z ≤ c8 z' := by | | apply Nat.div le div right | | unfold p8 | | gcongr <; omega''' | | new c8 = '''theorem c8 mono {z z' : Nat} h : z ≤ z' : c8 z ≤ c8 z' := by | | rw c8 def, c8 def | | apply Nat.div le div right | | rw p8 def, p8 def | | gcongr <; omega''' | | assert old c8 in src | | src = src.replace old c8, new c8 | | | | src = src.replace 'rcases Nat.le or lt j r with hle | hlt', 'rcases le or lt j r with hle | hlt' | | src = src.replace 'import FormalConjectures.Util.ProblemImports', | | 'import FormalConjectures.Util.ProblemImports\nset option linter.style.moduleDocstring false' | | open 'Dev/Checker.lean','w' .write src | | print "patched" | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | head -30 | | | | | | 49 --- TOOL bash --- | | patched | | Dev/Checker.lean:63:49: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | b ≥ 0 | | a ≥ 0 | | a - b ≥ 1 | | where | | a := ↑?m.28 | | b := ↑?m.30 | | Dev/Checker.lean:63:60: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | b ≥ 0 | | a ≥ 0 | | a - b ≥ 1 | | where | | a := ↑?m.29 | | b := ↑?m.31 | | Dev/Checker.lean:82:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/Checker.lean:82:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/Checker.lean:88:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/Checker.lean:88:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/Checker.lean:94:13: warning: this tactic is never executed | | | | | | | | 50 --- ASSISTANT --- | | I'm working through a Lean proof where omega can't handle the metavariable elaboration order, so I need to make the inequalities explicit by showing that 2 ≤ w+2 and 1 ≤ w+1 before applying mul le mul to establish that 2 ≤ w+2 w+1 . | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | src = src.replace ''' have h : 2 ≤ w+2 w+1 := Nat.mul le mul by omega by omega ''', | | ''' have h : 2 ≤ w+2 w+1 := by nlinarith''' | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" | head | | | | | | 50 --- TOOL bash --- | | Dev/Checker.lean:108:2: error: Tactic simp failed with a nested error: | | Dev/Checker.lean:133:9: error lean.unknownIdentifier : Unknown identifier le or lt | | Dev/Checker.lean:133:27: error: Tactic rcases failed: x✝ : ?m.72 is not an inductive datatype | | | | | | 51 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && sed -n '95,140p' Dev/Checker.lean | | | | | | 51 --- TOOL bash --- | | | | /- square filters -/ | | | | def maskBit mask u : Nat : Bool := Nat.beq Nat.land Nat.shiftRight mask u 1 1 | | | | def sqAll q mask : Nat fq : Nat : Bool := | | allB fun u = maskBit mask Nat.mod Nat.mul u u q fq 0 | | | | theorem sqAll sound {q mask fq : Nat} hq : 0 < q hle : q ≤ 2^fq | | h : sqAll q mask fq = true : ∀ j : Nat, maskBit mask j j % q = true := by | | intro j | | have hj : j % q < q := Nat.mod lt hq | | have := allB sound fq 0 h j % q Nat.zero le by omega | | simpa Nat.mul mod j j q using this | | | | /-- Newton iteration for isqrt; result is just a candidate, soundness never relies on it. -/ | | def newtonAux v : Nat : Nat → Nat → Nat := | | fun fuel = Nat.rec motive := fun = Nat → Nat | | fun g = g | | fun ih g = | | let g2 := Nat.div Nat.add g Nat.div v g 2 | | cond Nat.blt g2 g ih g2 g | | fuel | | | | def newton v : Nat : Nat := | | newtonAux v 64 Nat.pow 2 Nat.add Nat.div Nat.log2 v 2 1 | | | | /-- check r r < v < r+1 r+1 for r = newton v ; implies v is not a square. -/ | | def bracketOK v : Nat : Bool := | | let r := newton v | | Nat.blt Nat.mul r r v .and Nat.blt v Nat.mul Nat.add r 1 Nat.add r 1 | | | | theorem bracketOK sound {v : Nat} h : bracketOK v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | rw bracketOK, Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | simp only Nat.blt eq, Nat.mul eq, Nat.add eq at h1 h2 | | set r := newton v with hr | | rcases le or lt j r with hle | hlt | | · have : j j ≤ r r := Nat.mul le mul hle hle | | omega | | · have : r+1 r+1 ≤ j j := Nat.mul le mul hlt hlt | | omega | | | | end D | | | | | | 52 --- ASSISTANT --- | | I'm working through a proof issue in Lean where I need to simplify a term involving modular arithmetic. The goal requires beta reduction and applying Nat.mul mod to convert the nested modulo operations into a cleaner form, transforming maskBit mask Nat.mod Nat.mul j%q j%q q into maskBit mask j j % q . Writing the proof... I need to find the right lemma for the disjunction — le or lt should exist in Mathlib's order theory, but it might not be in scope without the right import or namespace. Let me try using Nat.lt or ge instead, which gives me either j < r+1 or j ≥ r+1 , and I can case split on that with rcases . | | | | For the simp lemmas, I'm looking for Nat.blt eq which should relate Nat.blt x y = true to x < y , and I'll need to handle the multiplication and addition lemmas carefully. Then I'll restructure the hypotheses h1 and h2 to work with the actual inequality I need. I need to find the right lemma connecting Nat.blt to Nat.lt — something like Nat.blt eq that gives me the equivalence I need. I'll check the exact name and potentially use Bool.and eq true for handling the conjunction, then fall back to simpa if the direct approach doesn't work. | | bash | | | | cd /workspace/leanproject && cat /tmp/chk.lean << 'EOF' | | import Mathlib | | check @Nat.blt eq | | check @Nat.ble eq | | check @Nat.beq eq | | check @le or lt | | example a b : Nat : Nat.mul a b = a b := rfl | | example a b : Nat : Nat.blt a b = a < b : Bool ... | | EOF | | sed -i 's/example a b : Nat : Nat.blt. //' /tmp/chk.lean && timeout 120 lake env lean /tmp/chk.lean 2 &1 | head | | | | | | 52 --- TOOL bash --- | | @Nat.blt eq : ∀ {x y : ℕ}, x.blt y = true = x < y | | @Nat.ble eq : ∀ {x y : ℕ}, x.ble y = true = x ≤ y | | @Nat.beq eq : ∀ {x y : ℕ}, x.beq y = true = x = y | | /tmp/chk.lean:5:8: error lean.unknownIdentifier : Unknown identifier le or lt | | | | | | 53 --- ASSISTANT --- | | I need to track down the correct function name for the comparison lemma in this Mathlib version—it looks like le or lt has been renamed, probably to Nat.lt or ge or something similar—and then update both bracketOK sound and sqAll sound to use the right one. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | old = ''' intro j | | have hj : j % q < q := Nat.mod lt hq | | have := allB sound fq 0 h j % q Nat.zero le by omega | | simpa Nat.mul mod j j q using this''' | | new = ''' intro j | | have hj : j % q < q := Nat.mod lt hq | | have h2 := allB sound fq 0 h j % q Nat.zero le by omega | | have e : j % q j % q % q = j j % q := by rw ← Nat.mul mod | | have h3 : maskBit mask j % q j % q % q = true := h2 | | rwa e at h3''' | | assert old in src; src = src.replace old, new | | | | old = '''theorem bracketOK sound {v : Nat} h : bracketOK v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | rw bracketOK, Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | simp only Nat.blt eq, Nat.mul eq, Nat.add eq at h1 h2 | | set r := newton v with hr | | rcases le or lt j r with hle | hlt | | · have : j j ≤ r r := Nat.mul le mul hle hle | | omega | | · have : r+1 r+1 ≤ j j := Nat.mul le mul hlt hlt | | omega''' | | new = '''theorem bracketOK sound {v : Nat} h : bracketOK v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | rw bracketOK, Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | set r := newton v with hr | | have h1' : r r < v := by rwa Nat.blt eq at h1 | | have h2' : v < r+1 r+1 := by rwa Nat.blt eq at h2 | | rcases Nat.lt or ge j r+1 with hle | hge | | · have : j j ≤ r r := Nat.mul le mul by omega by omega | | omega | | · have : r+1 r+1 ≤ j j := Nat.mul le mul hge hge | | omega''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" | head | | | | | | 53 --- TOOL bash --- | | | | 54 --- ASSISTANT --- | | Part 1 of Checker.lean is working, so now I'm moving to part 2 to add the leaf and tree layer with mask constants pulled from files, along with the test theorems for each dimension and the master theorem connecting to the A306477 sequence. I'm setting up the mask literals and then using the decide tactic plus kernel computation to verify the sqAll theorems—these will take a bit since they're working through thousands of leaves with multiplication, modulo, and bit shift operations. | | | | Now I'm defining the mask constants Q1, M1, etc., and proving that sqAll returns true for each via decide, then deriving the soundness theorem that says if a number passes the mask test, it can't be a perfect square. The sqTest function chains these mask checks together with early exits—if any mask rejects the candidate, we immediately return true not a square , otherwise we fall through to the bracket check for the final verification. | | | | For the soundness proof, I need to show that if sqTest returns true, then no j satisfies j² = v. The strategy is to assume j² = v and derive a contradiction by showing that the mask checks would have caught it—specifically, mask1 all guarantees that j² mod Q1 is in the mask, so rewriting v with j² and unfolding sqTest should expose the contradiction in the cond chain. | | | | The tricky part is handling the syntactic mismatch between Nat.mod and % notation. After simp unfolds sqTest, the goal might normalize v % Q1 differently than how mask1 all constructs its proof with the % operator. I need to either construct an intermediate lemma that bridges the two spellings, or rely on rw's defeq matching to handle the conversion automatically. Rewriting the contradiction by aligning the notation between maskBit M1 Nat.mod v Q1 and the lemma statement, then using simp or direct substitution to derive true = false from the conflicting equalities. The elaborator uses default transparency to unfold instances during unification, so the defeq check succeeds without triggering evaluation on variable-containing terms like maskBit M1 v % Q1 . Rather than wrestling with all this notation and defeq complexity, I should just define everything using standard notation in the hot definitions and let the system handle the rest. | | | | For the cost concern — each operation would need about 4 delta-unfolds of small constants like instance chains, which the kernel doesn't cache but are cheap allocations, so maybe 1.5-2× slower overall. I'll keep the core Nat. operations in hot definitions but write all the spelling bridges as explicit rfl lemmas stated once, like equating Nat.mod with the % operator and similar for the other operations. | | | | Then in soundness proofs I'll normalize everything upfront with simp only using those lemmas to convert to standard notation, keeping things clean and robust. | | | | Now for the leafX function — I'm computing a binomial coefficient by multiplying four consecutive integers and dividing by 24, then checking if a threshold is exceeded or running a square test on a derived value. | | | | I realize c4 x gets computed twice when the condition is false, so I should let-bind it to avoid redundant calculation in the kernel. But kernel let reduction just substitutes the expression into both branches without sharing, meaning c4 x still evaluates twice on the main path — once for the guard and once inside the sqTest branch, adding about 5 extra operations per leaf. | | | | I'm trying to optimize this by extracting a helper function that takes the computed value as an argument, but the kernel still uses call-by-name substitution without memoization, so the argument term gets duplicated and re-evaluated at each use site. The real question is whether the kernel caches intermediate whnf results by expression pointer when it needs to evaluate the same term multiple times. The Lean 4 kernel does cache weak head normal form evaluations in a map keyed by expression pointer, which means shared subterms avoid redundant computation—so keeping the let-binding is fine since beta substitution preserves pointer sharing. Now I'm defining the actual leafX function that uses a cached c4 computation and conditionally applies the square test, along with its soundness proof. Continuing the proof by establishing that W is strictly less than c4 x using the negation from the false case, then setting up an equation relating the squared term to the expression involving w. I need to unfold leafX using simp with the equation lemma, and handle the cond simplification by applying hb and Bool.cond false to reduce the conditional expression. Now I'm defining xtreeOK as a function that checks some property... | | | | Writing proof structure... I'm verifying the inequality chain where W ≤ c4 2^fx ≤ c4 x holds, which contradicts the assumption that t2 ≥ 1. The leafY case follows similarly, and I need to apply beta reduction to show that allB sound gives us the predicate evaluation we need. Now I'm setting up the master theorem statement with the top-level bounds on N and the recursive structure. | | | | For the bridge to sequence A306477, I'm establishing that if no combination of t2 w + c4 x + c6 y + c8 z equals N, then A306477 N = 0. I'll need to define A306477 locally during development to validate the proof before moving it to the final file. I'm also proving that the binomial coefficient w+2 choose 2 equals t2 w by expanding it as w+2 w+1 /2. | | | | Now I'm working through the tactic proof—checking whether rw Nat.choose two right ; rfl handles the subtraction w+2 -1 = w+1 automatically through definitional equality, since Nat.sub on successor terms should reduce by recursion. I'm considering using simp Nat.choose two right, t2 def ; ring nf or rw Nat.choose two right, t2 def ; congr 1; omega to handle the numerator equality, though omega might struggle with the multiplication involved. | | | | For the choose4 eq lemma, I need to rewrite using the descending factorial definition and show that x+3 .descFactorial 4 / 24 equals c4 x, where 24 is factorial 4. I'm planning to use norm num to establish the factorial value, then simplify the descending factorial expression. | | | | The key challenge is handling the natural number subtraction in the descending factorial expansion—x+3-3, x+3-2, etc.—which simplifies to x, x+1, x+2, x+3. I'm thinking I can establish this equality with a have statement using simp with Nat.add sub cancel, then apply ring to show the numerators match after canceling the denominator. | | Part 1 compiled successfully. Now I'm moving on to part 2, which covers masks, sqTest, leaf/tree functions, and their soundness lemmas. | | bash | | | | cd /workspace/leanproject && M1=$ cat /tmp/mask 7425.txt && M2=$ cat /tmp/mask 10829.txt && M3=$ cat /tmp/mask 12673.txt && cat Dev/Checker.lean << EOF | | | | namespace D | | | | /- notation bridges -/ | | theorem mul eqn a b : Nat : Nat.mul a b = a b := rfl | | theorem add eqn a b : Nat : Nat.add a b = a + b := rfl | | theorem sub eqn a b : Nat : Nat.sub a b = a - b := rfl | | theorem div eqn a b : Nat : Nat.div a b = a / b := rfl | | theorem mod eqn a b : Nat : Nat.mod a b = a % b := rfl | | theorem pow eqn a b : Nat : Nat.pow a b = a ^ b := rfl | | | | /- the three square masks -/ | | def Q1 : Nat := 7425 | | def Q2 : Nat := 10829 | | def Q3 : Nat := 12673 | | def M1 : Nat := $M1 | | def M2 : Nat := $M2 | | def M3 : Nat := $M3 | | | | set option maxHeartbeats 1000000 in | | theorem sqAllM1 : sqAll Q1 M1 13 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllM2 : sqAll Q2 M2 14 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllM3 : sqAll Q3 M3 14 = true := by decide +kernel | | | | theorem mask1 all : ∀ j : Nat, maskBit M1 j j % Q1 = true := | | sqAll sound by norm num Q1 by norm num Q1 sqAllM1 | | theorem mask2 all : ∀ j : Nat, maskBit M2 j j % Q2 = true := | | sqAll sound by norm num Q2 by norm num Q2 sqAllM2 | | theorem mask3 all : ∀ j : Nat, maskBit M3 j j % Q3 = true := | | sqAll sound by norm num Q3 by norm num Q3 sqAllM3 | | | | /-- composite "is v possibly a square" test with early-outs; true result proves nothing, | | result true of the whole leaf chain means: v is certainly NOT a square, OR the | | branch was never reached. Precisely: sqTest v = true → v is not a square. -/ | | def sqTest v : Nat : Bool := | | cond maskBit M1 Nat.mod v Q1 | | cond maskBit M2 Nat.mod v Q2 | | cond maskBit M3 Nat.mod v Q3 | | bracketOK v | | true | | true | | true | | | | theorem sqTest sound {v : Nat} h : sqTest v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | have m1 : maskBit M1 Nat.mod v Q1 = true := by | | have := mask1 all j; rw hj at this; exact this | | have m2 : maskBit M2 Nat.mod v Q2 = true := by | | have := mask2 all j; rw hj at this; exact this | | have m3 : maskBit M3 Nat.mod v Q3 = true := by | | have := mask3 all j; rw hj at this; exact this | | rw sqTest, m1, m2, m3 at h | | simp only cond true at h | | exact bracketOK sound h j hj | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" | head | | | | | | 54 --- TOOL bash --- | | | | 55 --- ASSISTANT --- | | The kernel checks compiled successfully and passed their time constraints, which is a good sign even though the machine is still running the scan. Now I'm moving through the next phase with leafX, xtreeOK, leafY, ytreeOK, leafZ, and master, while also monitoring the scan's progress. | | bash | | | | tail -1 /tmp/scan99.err | | | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | | | namespace D | | | | /- leaf and tree checkers -/ | | | | /-- check that t2 w + c4 x ≠ W for all w , at this particular x . -/ | | def leafX W x : Nat : Bool := | | let c := c4 x | | cond Nat.ble W c true sqTest Nat.add Nat.mul 8 Nat.sub W c 1 | | | | theorem leafX sound {W x : Nat} h : leafX W x = true : ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | cases hb : Nat.ble W c4 x with | | | true = | | rw Nat.ble eq at hb | | omega | | | false = | | have hnb : ¬ W ≤ c4 x := by rw ← Nat.ble eq, hb ; simp | | simp only leafX, hb, cond false at h | | have hv : Nat.add Nat.mul 8 Nat.sub W c4 x 1 = 2 w+3 2 w+3 := by | | simp only add eqn, mul eqn, sub eqn | | have hm : W - c4 x = t2 w := by omega | | rw hm, eight t2 | | rw hv at h | | exact sqTest sound h 2 w+3 rfl | | | | /-- check that t2 w + c4 x ≠ W for all w x . -/ | | def xtreeOK W : Nat : Bool := | | let fx := Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 | | allB leafX W fx 0 .and Nat.ble W c4 Nat.pow 2 fx | | | | theorem xtreeOK sound {W : Nat} h : xtreeOK W = true : ∀ w x, t2 w + c4 x ≠ W := by | | intro w x heq | | simp only xtreeOK at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge x 2 ^ Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 with hx | hx | | · have hl := allB sound 0 h1 x Nat.zero le by omega | | exact leafX sound hl w heq | | · have hc : c4 Nat.pow 2 Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 ≤ c4 x := by | | apply c4 mono | | rw pow eqn | | exact hx | | omega | | | | /-- check that t2 w + c4 x + c6 y + r8 ≠ N for all w x , at this y r8 = c8 z . -/ | | def leafY N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK Nat.sub N b | | | | theorem leafY sound {N r8 y : Nat} h : leafY N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← Nat.ble eq, hb ; simp; rfl | | simp only leafY, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK sound h w x this | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A4 | head -30 | | | | | | 55 --- TOOL bash --- | | block 4/24 done marks=155631497535 zeros=0 | | | | | | 55 --- TOOL bash --- | | Dev/Checker.lean:263:57: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | N.ble r8.add c6 y | | in the target expression | | ¬N.ble r8 + c6 y = true | | | | | | | | 56 --- ASSISTANT --- | | I'm working through a proof where I need to handle the false branch of a boolean comparison. The issue is that when Nat.ble N Nat.add r8 c6 y evaluates to false, I'm rewriting the hypothesis using the equivalence between ble and equality to transform the goal into a negation, but I need to make sure the arithmetic expression aligns correctly across the rewrite. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | old = ''' have hnb : ¬ N ≤ r8 + c6 y := by rw ← Nat.ble eq, hb ; simp; rfl''' | | new = ''' have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A4 | head -20 | | | | | | 56 --- TOOL bash --- | | | | 57 --- ASSISTANT --- | | I've cleaned up the y-tree and leafZ references, fixed the fuel FY parameter, and I'm ready to continue. | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | | | namespace D | | | | /-- check t2 w + c4 x + c6 y + r8 ≠ N for all w x y , given fuel fy for the y-tree. -/ | | def ytreeOK N fy r8 : Nat : Bool := | | allB leafY N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | theorem ytreeOK sound {N fy r8 : Nat} h : ytreeOK N fy r8 = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | simp only ytreeOK at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | /-- check t2 w + c4 x + c6 y + c8 z ≠ N for all w x y , at this z . -/ | | def leafZ N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true ytreeOK N fy r8 | | | | theorem leafZ sound {N fy z : Nat} h : leafZ N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ, hb, cond false at h | | exact ytreeOK sound h w x y heq | | | | /-- the master criterion: no w,x,y,z with t2 w + c4 x + c6 y + c8 z = N . -/ | | theorem master {N fy fz : Nat} | | h : allB leafZ N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | /- bridge from choose to the polynomial forms -/ | | | | theorem choose2 eq w : Nat : w+2 .choose 2 = t2 w := by | | rw Nat.choose two right, t2 def | | congr 1 | | omega | | | | theorem choose4 eq x : Nat : x+3 .choose 4 = c4 x := by | | rw Nat.choose eq descFactorial div factorial, c4 def, p4 def | | congr 1 | | · simp Nat.descFactorial | | ring nf | | omega | | · rfl | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A6 | head -30 | | | | | | 57 --- TOOL bash --- | | Dev/Checker.lean:324:2: error: No goals to be solved | | Dev/Checker.lean:331:4: error: No goals to be solved | | Dev/Checker.lean:332:2: error: No goals to be solved | | | | | | 58 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && sed -n '315,335p' Dev/Checker.lean && cat /tmp/probe.lean << 'EOF' | | import Mathlib | | example x : Nat : x+3 .choose 4 = x x+1 x+2 x+3 /24 := by | | rw Nat.choose eq descFactorial div factorial | | congr 1 | | simp Nat.descFactorial | | ring | | example w : Nat : w+2 .choose 2 = w+2 w+1 /2 := by | | rw Nat.choose two right | | EOF | | timeout 200 lake env lean /tmp/probe.lean 2 &1 | head -20 | | | | | | 58 --- TOOL bash --- | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | /- bridge from choose to the polynomial forms -/ | | | | theorem choose2 eq w : Nat : w+2 .choose 2 = t2 w := by | | rw Nat.choose two right, t2 def | | congr 1 | | omega | | | | theorem choose4 eq x : Nat : x+3 .choose 4 = c4 x := by | | rw Nat.choose eq descFactorial div factorial, c4 def, p4 def | | congr 1 | | · simp Nat.descFactorial | | ring nf | | omega | | · rfl | | | | end D | | /tmp/probe.lean:7:54: error: unsolved goals | | w : ℕ | | ⊢ w + 2 w + 2 - 1 / 2 = w + 2 w + 1 / 2 | | | | | | 59 --- ASSISTANT --- | | The first probe example worked smoothly with the congruence tactic and ring solver, but choose2 is giving me trouble. After rewriting, I get the goal w+2 w+2-1 /2 = w+2 w+1 /2, which should resolve with congruence and omega, yet in the Checker the congruence tactic seems to be closing more than expected—throwing a "no goals" error that suggests the rewrite itself might be doing more work than anticipated. | | | | Looking at the defeq chain: since w+2 is succ succ w , subtracting 1 gives succ w, which is defeq to w+1, so congruence can actually close the goal by reflexivity without needing omega. The same pattern appears in choose4 where congruence closes both goals prematurely, leaving nothing for the downstream tactics. I should simplify by dropping the redundant tactics and using try variants for robustness, or just end with congruence and skip the final omega entirely. | | bash | | | | cd /workspace/leanproject && cat /tmp/probe2.lean << 'EOF' | | import Mathlib | | example w : Nat : w+2 .choose 2 = w+2 w+1 /2 := by | | rw Nat.choose two right ; congr 1 | | example x : Nat : x+3 .choose 4 = x x+1 x+2 x+3 /24 := by | | rw Nat.choose eq descFactorial div factorial | | congr 1 | | simp Nat.descFactorial | | ring | | example y : Nat : y+5 .choose 6 = y y+1 y+2 y+3 y+4 y+5 /720 := by | | rw Nat.choose eq descFactorial div factorial | | congr 1 | | · simp Nat.descFactorial | | ring | | · decide | | example z : Nat : z+7 .choose 8 = z z+1 z+2 z+3 z+4 z+5 z+6 z+7 /40320 := by | | rw Nat.choose eq descFactorial div factorial | | congr 1 | | · simp Nat.descFactorial | | ring | | · decide | | EOF | | timeout 200 lake env lean /tmp/probe2.lean 2 &1 | head -20 | | | | | | 59 --- TOOL bash --- | | /tmp/probe2.lean:14:2: error: No goals to be solved | | /tmp/probe2.lean:20:2: error: No goals to be solved | | | | | | 60 --- ASSISTANT --- | | For choose6 and choose8 , the congr 1 tactic closes out to a single goal through definitional equality, so I can remove the decide bullets and apply the simpler single-goal approach instead. Then I'll update the Checker with the final bridge lemmas. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | old = '''theorem choose2 eq w : Nat : w+2 .choose 2 = t2 w := by | | rw Nat.choose two right, t2 def | | congr 1 | | omega | | | | theorem choose4 eq x : Nat : x+3 .choose 4 = c4 x := by | | rw Nat.choose eq descFactorial div factorial, c4 def, p4 def | | congr 1 | | · simp Nat.descFactorial | | ring nf | | omega | | · rfl | | | | end D''' | | new = '''theorem choose2 eq w : Nat : w+2 .choose 2 = t2 w := by | | rw Nat.choose two right, t2 def | | congr 1 | | | | theorem choose4 eq x : Nat : x+3 .choose 4 = c4 x := by | | rw Nat.choose eq descFactorial div factorial, c4 def, p4 def | | congr 1 | | simp Nat.descFactorial | | ring | | | | theorem choose6 eq y : Nat : y+5 .choose 6 = c6 y := by | | rw Nat.choose eq descFactorial div factorial, c6 def, p6 def | | congr 1 | | simp Nat.descFactorial | | ring | | | | theorem choose8 eq z : Nat : z+7 .choose 8 = c8 z := by | | rw Nat.choose eq descFactorial div factorial, c8 def, p8 def | | congr 1 | | simp Nat.descFactorial | | ring | | | | end D''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A4 | head -20 | | | | | | 60 --- TOOL bash --- | | | | 61 --- ASSISTANT --- | | The framework compiles successfully. Now I'm connecting the final piece: defining A306477 with the zero condition and building out the disproof skeleton using a placeholder N. Testing with small values, I find that only n=0 satisfies A306477 n = 0, and verifying this case: the w loop shows w+2 .choose2 ≥ 1 0, so the sum equals zero, confirming A306477 0 = 0. The master inequality also holds for N=0 since t2+... ≥ 1 0, and the checker validates with leafZ. | | | | Now I'm testing the full pipeline with N=0, fy=1, fz=1 to confirm all the plumbing works end-to-end. The bridge lemma unfolds A306477 and applies sum eq zero repeatedly across the four nested loops, then uses if neg to discharge the inequality goal by rewriting the four choose expressions and applying the hypothesis that no combination of the weighted terms equals N. | | | | I need to verify the dev copy of A306477 matches the submission exactly, then test the final theorem shape with N=0 by applying the master proof with those specific parameters and adding it to the dev file to compile. | | Framework compiles. Now add the A306477 bridge and validate the full pipeline end-to-end with N=0: | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | | | open Nat Finset in | | def A306477 n : ℕ : ℕ := | | let R := Finset.range n + 1 | | R.sum fun w = | | R.sum fun x = | | R.sum fun y = | | R.sum fun z = | | if w + 2 .choose 2 + x + 3 .choose 4 + y + 5 .choose 6 + z + 7 .choose 8 = n then 1 else 0 | | | | | | | | | | | | namespace D | | | | theorem A eq zero {N : Nat} hN : ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N : | | A306477 N = 0 := by | | simp only A306477 | | apply Finset.sum eq zero; intro w | | apply Finset.sum eq zero; intro x | | apply Finset.sum eq zero; intro y | | apply Finset.sum eq zero; intro z | | rw if neg | | rw choose2 eq, choose4 eq, choose6 eq, choose8 eq | | exact hN w x y z | | | | -- end-to-end plumbing validation on N = 0 | | theorem test0 : A306477 0 = 0 := | | A eq zero master N:=0 fy:=1 fz:=1 by decide +kernel by decide +kernel | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A6 | head -30 | | | | | | 61 --- TOOL bash --- | | | | 62 --- ASSISTANT --- | | The full pipeline is compiling successfully with the test cases. Now I need to benchmark the actual checker performance—I'll set up a large fake value around 1e12 that has representations so the checker can do a complete traversal rather than returning false early, which will give me accurate timing measurements for the full pass. Even with contention from the scan process, the timing should be usable since Lean gets roughly one core's worth of resources. I'm setting up the benchmark with N = 999999999986 and calculating the necessary depths: fz = 8 gives c8 2^8 ≈ 1.2e15 which exceeds 1e12, and fy = 9 gives c6 2^9 ≈ 2.6e13, also sufficient. The total leaf count across all valid z,y pairs should be around 1.3–2× the raw triple count of roughly 67 million. | | | | Rather than bench the full tree which would take an hour or more, I'll sample strategically: time a single z value like z = 30 to get representative work costs, then extrapolate based on slice sizes I can compute in Python. I'll also check z = 200 as a cheap-path baseline. For a more focused micro-benchmark, I can isolate a single z,y pair with W ≈ 9e11, which gives about 4096 leaves, and measure just the xtreeOK kernel time using Lean's decide tactic to get precise timing. | | | | To extract per-leaf cost, I'll subtract the file overhead around 13 seconds by timing a null file, then run two theorems with different leaf counts—say 4096 vs 8192 leaves—to calculate the slope. I need to use different W values to avoid kernel caching, then directly time the allB calls with fuel 12 versus 13 to isolate the per-leaf contribution, keeping in mind that beyond X̄ ≈ 2155 the cheap-path kicks in. | | | | For the full-work leaf cost specifically, I'll compare fuel 10 1024 leaves all doing full work against fuel 11 2048 leaves all full , giving me a 1024-leaf slope. I'll write two theorems in separate files—one with fuel 10 and one with fuel 11—then time the difference to extract the per-full-leaf cost. The benchLeafX function needs to force the leaf computation fully by combining it with a boolean operation. | | | | To avoid pointer-sharing issues where the same subterm might not be duplicated after optimization, I'll bind the leaf computation to a variable first, then use that variable in both branches of the boolean operation—this ensures the pointer is shared consistently through zeta reduction. | | The end-to-end pipeline is working correctly. Now I'll benchmark the actual per-leaf kernel cost. | | bash | | | | cd /workspace/leanproject && head -50 Dev/Checker.lean /dev/null; cat /tmp/bench10.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | EOF | | sed '1,2d' Dev/Checker.lean /tmp/bench10.lean | | cat /tmp/bench10.lean << 'EOF' | | | | namespace D | | def benchLeafX W x : Nat : Bool := | | let b := leafX W x | | b.or Bool.not b | | set option maxHeartbeats 0 in | | theorem bx10 : allB benchLeafX 908070605043 10 0 = true := by decide +kernel | | end D | | EOF | | sed 's/bx10 : allB benchLeafX 908070605043 10 0/bx11 : allB benchLeafX 908070605043 11 0/' /tmp/bench10.lean /tmp/bench11.lean | | time timeout 280 lake env lean /tmp/bench10.lean 2 &1 | head -3 | | | | | | 62 --- TOOL bash --- | | | | real 0m34.330s | | user 0m10.084s | | sys 0m2.069s | | | | /tmp/bench10.lean:82:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | | | | | 63 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && time timeout 280 lake env lean /tmp/bench11.lean 2 &1 | grep -c error | | | | | | 63 --- TOOL bash --- | | <stdout 0 | | </stdout | | <stderr | | real 0m25.367s | | user 0m10.550s | | sys 0m1.903s | | </stderr | | <returncode 1</returncode | | | | 64 --- ASSISTANT --- | | The performance metrics are interesting—fuel 10 with 1024 leaves took 34.3 seconds real time but only 10.1 seconds user time, while fuel 11 with 2048 leaves was faster at 25.4 seconds real with 10.6 seconds user. The user times are nearly identical, which suggests the leaf computation itself is negligible compared to the ~10 second baseline from file compilation and framework overhead. The difference in user time between the two runs is only about 0.5 seconds for 1024 extra leaves, which could be around 0.5 milliseconds per leaf or just noise in the measurements. | | | | Real time is being dominated by contention, so I need to run a much larger benchmark to see meaningful differences. I'm setting up a test that varies the leaf count significantly—comparing fuel 11 with 2048 full leaves against fuel 15 with 32768 leaves, where the extra leaves beyond a certain threshold use the cheap path. To make this cleaner, I'll define a benchmark that replicates the x-range work by varying multiple W values across different pair indices, then run benchmarks over pairs with fuel 4 16 pairs = 32768 full leaves versus fuel 5 32 pairs = 65536 leaves , giving me a delta of 32768 leaves to measure against. | | Leaf cost is buried in baseline noise; scale up with multiple W values: | | bash | | | | cd /workspace/leanproject && head -n -7 /tmp/bench10.lean /tmp/benchbase.lean && cat /tmp/benchbase.lean << 'EOF' | | | | namespace D | | def benchLeafX W x : Nat : Bool := | | let b := leafX W x | | b.or Bool.not b | | def benchPair p : Nat : Bool := allB benchLeafX Nat.sub 908070605043 Nat.mul 977 p 11 0 | | set option maxHeartbeats 0 in | | theorem bp : allB benchPair FUELP 0 = true := by decide +kernel | | end D | | EOF | | sed 's/FUELP/4/' /tmp/benchbase.lean /tmp/bench4.lean | | sed 's/FUELP/6/' /tmp/benchbase.lean /tmp/bench6.lean | | time timeout 280 lake env lean /tmp/bench4.lean 2 &1 | grep -c "error"; time timeout 280 lake env lean /tmp/bench6.lean 2 &1 | grep -c "error" | | | | | | 64 --- TOOL bash --- | | <stdout 0 | | 0 | | </stdout | | <stderr | | real 1m12.167s | | user 0m15.832s | | sys 0m2.135s | | | | real 2m23.061s | | user 0m31.576s | | sys 0m2.489s | | </stderr | | <returncode 1</returncode | | | | 65 --- ASSISTANT --- | | Looking at the performance metrics across different fuel levels, I'm seeing consistent leaf processing times around 160 microseconds per leaf, with fuel 4 showing about 5.5 seconds for 32,768 leaves and fuel 6 hitting 21.3 seconds delta from baseline for 131,072 leaves—the timing is holding steady despite the scale difference, though there's some user-time contention happening in the kernel. | | | | Extrapolating to 100 million leaves would mean roughly 4.4 hours single-threaded, which is much slower than I'd hoped. Breaking down what's happening in each leaf: the core arithmetic 3 multiplications, 3 additions, 1 division plus the boolean logic and bit operations should only need 25-30 primitive reductions, but I'm seeing 5-6 microseconds per reduction—likely due to overhead from unfolding the recursive motive lambda in the Nat.rec and the Decidable wrapper around the kernel evaluation, plus computing large literals like Nat.pow 2 f repeatedly. | | | | To speed this up, I could try reducing the number of reductions per leaf by inlining everything into a single arithmetic expression with minimal control flow, though the mask testing approach inherently requires conditional chains, so I'd need to explore packing more work into each primitive operation. The real bottleneck is likely the kernel overhead from the Nat.rec machinery itself—instantiating function types and managing the reduction loop—rather than the arithmetic operations on the 40-bit values. I should profile just the node cost in isolation by testing allB on a trivial leaf, then explore whether a different loop structure using List.all and List.range could be more efficient than the current Nat.rec approach. | | | | For the x-loop optimization, I'm thinking about filtering to only admissible residues—values of x whose residues can actually satisfy the square condition modulo q—rather than iterating through all x values. The challenge is that computing which x residues pass the mask inside Lean either requires pre-computed certificate lists which get too large or in-kernel computation of admissibility. | | | | Another angle: restructure the search as x-strips, handling 8 consecutive x values per leaf with a precomputed 8-bit mask to mark which ones are valid. | | | | On the scale side, finding a smaller counterexample around n₀ ~ 2e11 would give roughly 2.8e7 triples and run in about 1.2 hours—much more tractable. Even n₀ ~ 4e12 with ~2e8 leaves would take around 9 hours, which is tight but feasible within a 72-hour budget on a single thread. | | | | I'm also considering whether I can parallelize across multiple theorems... Testing the parallel elaboration hypothesis with multiple copies of the benchmark to see if real-time stays constant or scales linearly. Also need to profile node costs from test b to guide micro-optimizations, while the scan continues in the background. | | I've estimated the kernel time at around 4 hours for the current scale, so I'm going to test whether Lean can parallelize elaboration across independent theorems to speed things up. | | bash | | | | cd /workspace/leanproject && head -n -3 /tmp/benchbase.lean /tmp/benchpar.lean && cat /tmp/benchpar.lean << 'EOF' | | set option maxHeartbeats 0 in | | theorem bpA : allB benchPair 4 0 = true := by decide +kernel | | set option maxHeartbeats 0 in | | theorem bpB : allB benchPair 4 16 = true := by decide +kernel | | set option maxHeartbeats 0 in | | theorem bpC : allB benchPair 4 32 = true := by decide +kernel | | set option maxHeartbeats 0 in | | theorem bpD : allB benchPair 4 48 = true := by decide +kernel | | end D | | EOF | | time timeout 280 lake env lean /tmp/benchpar.lean 2 &1 | grep -c "error" | | | | | | 65 --- TOOL bash --- | | <stdout 0 | | </stdout | | <stderr | | real 1m25.591s | | user 0m30.008s | | sys 0m2.338s | | </stderr | | <returncode 1</returncode | | | | 66 --- ASSISTANT --- | | I'm analyzing the performance metrics for running four heavy theorems—the user time of 30 seconds aligns with my baseline estimate of 10 seconds plus 4 theorems at 5.5 seconds each. However, the real elapsed time of 85.6 seconds versus 72 seconds for a single-theorem file suggests the machine was under contention from other processes, making the wall-clock measurements unreliable. Since user time represents total CPU seconds consumed, parallel execution would ideally show real time as baseline plus the longest individual theorem, but system contention obscures that relationship. | | | | Comparing the fuel6 file with one theorem 64 pairs, 31.6s user, 143s real against this file with four theorems same 64 pairs total, 30s user, 85.6s real shows the real time is significantly lower, which indicates some parallelism is happening despite the scan99 process consuming 16 threads. I should pause the scan process momentarily using SIGSTOP to get a clean benchmark on an idle machine, since the scan is only a few hours in and a 2-minute pause is negligible. | | I'm pausing the scanner briefly to get clean benchmarks and check for parallelism patterns. | | bash | | | | pkill -STOP -x scan99 && sleep 1 && cd /workspace/leanproject && time timeout 280 lake env lean /tmp/benchpar.lean 2 &1 | grep -c error; time timeout 280 lake env lean /tmp/bench6.lean 2 &1 | grep -c error; pkill -CONT -x scan99; echo resumed | | | | | | 66 --- TOOL bash --- | | | | real 0m29.515s | | user 0m28.696s | | sys 0m2.325s | | | | real 0m32.683s | | user 0m31.240s | | sys 0m2.738s | | | | 0 | | 0 | | resumed | | | | | | 67 --- ASSISTANT --- | | Looking at the benchmark results, the real and user times are nearly identical for both benchpar and bench6, which tells me there's no parallel elaboration happening—everything's running single-threaded. Breaking down the per-leaf overhead from the baseline difference gives me about 160 microseconds of configuration time per leaf. | | | | The real constraint here is that the verifier will compile this as a single file with unknown hardware and time limits, so a 4-hour single-threaded proof could easily exceed whatever timeout they have. I need to aggressively optimize the per-leaf cost. My plan is to profile what's actually expensive: test with a trivial leaf function to isolate node overhead, then try just the c4 computation, and explore whether replacing the Nat.rec recursion with a binary tree structure could help. I'm also wondering if decide with kernel reduction is doing more work than I think—it might be evaluating the decision procedure before constructing the proof term. So the kernel evaluates twice: once during elaboration when decide +kernel calls Kernel.isDefEq to pre-check, then again at addDecl when the proof term of decide eq true Eq.refl true is typechecked. To avoid this double cost, I could bypass the elaborator entirely by constructing the declaration directly through metaprogramming—using open Lean in run cmd to manually build the proof term and add it via addDecl , which would trigger only a single kernel evaluation. | | | | Writing metaprogramming example... I'm checking whether run cmd with addDecl is allowed in the submission—it's just elaboration-time metaprogramming that produces a normal kernel-checked theorem with no extra axioms, so it should pass verification. The key concern is whether addDecl triggers re-elaboration, but it only does kernel typechecking for theorems, so there's no extra compilation overhead. I should verify empirically whether this approach actually gives the 2× speedup by comparing timing against the decide version. | | | | Now I'm looking at further optimizations to reduce reductions per leaf: inlining constants into the leaf body, checking whether cond or pattern matching is more efficient, and analyzing the allB node computation where Nat.pow 2 f gets computed at each node—that's already fast with a built-in path, but I could precompute the stride by passing it down the recursion instead. The bigger potential issue is kernel whnf cache misses when unfolding Nat.rec repeatedly, which creates fresh closures each time. | | | | Looking at the performance numbers, each leaf reduction takes around 6 microseconds, likely because Nat.rec motive instantiation is expensive with universe instantiation and pi type creation. The key optimization is increasing leaf arity by unrolling multiple x-values in a single leaf body—handling a strip of 8 x-values sequentially without recursion—which divides tree overhead by 8 while keeping the per-x work constant. | | | | Before diving into optimizations, I should profile three things: the baseline cost of a trivial leaf with allB , then measure just the c4 computation, then add modulo and masking to isolate where time is spent. | | | | The real bottleneck is the x-loop with ~90 million evaluations, each doing ~26 reductions. Instead of testing each x individually, I could vectorize by packing multiple x-values into big-number operations—computing an entire strip's filter test in a few GMP operations by treating the strip as a single large number and extracting the relevant bits. | | | | The key insight is using polynomial multipoint evaluation: I can encode all 64 polynomial values into one huge number via a base-B encoding trick, where B is large enough to separate the results. This reduces the problem to precomputing five constants the sums of powers weighted by B and then combining them with the polynomial coefficients in a single multiplication. Now I'm working through the per-slot modular reduction: computing 8t+1 mod 7425 for each slot, where t comes from the packed representation. The challenge is that modular reduction isn't directly sliceable across slots, so I'm exploring whether I can compute t mod m per slot using the standard formula u = t − m·floor t/m , though extracting the floor operation per slot is tricky. | | | | I'm considering alternatives: setting B ≡ 1 mod 7425·8 to avoid mixing slots, or using a quadratic-residue check instead of direct modular arithmetic. The vectorized approach hits a wall here, so I'm weighing whether to extract slots individually anyway—shifting and masking per x takes only 2 operations, which saves the c4 computation and bundled arithmetic, leaving roughly 8-10 operations per slot versus 26 without vectorization, giving about a 2.5× speedup that might be worth the added complexity. | | | | The key insight is restructuring the inner loop to carry the packed number down through x-recursion as an explicit linear recursion of depth 64 stack is fine , shifting right by 64 bits each step. Per-slot operations drop to around 12 versus 26, yielding a 2.2× improvement, and combined with the single-eval addDecl optimization, the total speedup reaches roughly 4.4×, bringing the time down to about 36 microseconds per leaf. | | | | At 9×10^7 leaves, this scales to roughly 55 minutes total. For the survivors about 9.8% that still need mask2/3 via the normal path, there's some extra recomputation of v, but that's acceptable. I'm exploring whether precomputing the packed remainders modulo 7425 could eliminate the per-x modulo operation entirely, though expressing this as a polynomial evaluation mod m and packing those values is proving tricky. | | | | The cleaner approach is just extracting remainders per slot with about 12 operations per x. I'm also considering whether choosing the base B such that B ≡ 1 mod m could simplify things—if so, the packed value mod m would just sum the individual remainders—but that doesn't help much. The alternative of computing packedV mod some larger modulus per slot doesn't seem to work either. | | | | So the plan is: first confirm the single-kernel evaluation trick works and measure its performance, then profile the actual node costs, and if needed implement the packed inner loop with proper soundness guarantees—which means proving that extracting a digit from the packed representation actually gives the correct c4 value, requiring careful arithmetic lemmas about base-2^64 digit extraction. | | | | The alternative is to have the checker verify the packing at runtime by reconstructing values, though that's expensive. Another angle: verify the packed literal once per strip using five anchor point identities—if a degree-4 polynomial agrees at five points, that should verify everything, but the challenge is that the packed number is given as a computed expression rather than a certificate, so carries between slots could break the invariant. | | | | The core issue is that P X = c4 a+X has all positive coefficients when a and X are non-negative, but packing p4 directly the product before dividing by 24 requires handling the division per slot—that's an extra 13 operations per evaluation. Packing p4/24 exactly would require non-integer coefficients, which isn't feasible, so the approach is to pack p4 and divide by 24 at each slot. | | | | Now I'm working through the soundness proof for this packing scheme: I need to show that extracting each 64-bit slot from the packed representation and dividing by 24 recovers the correct polynomial value. The key is proving that the packed value equals the sum of all p4 a+X terms shifted by their respective bit positions, which should follow from expanding the polynomial identity across the finite range of X values. } v X·B^X where each v X < B, I can extract the k-th digit using a right shift and bitwise AND: E 64k &&& B−1 = v k. This works by induction over the 64 terms, assuming each v X stays below B, which requires bounding a+63 to around 2213. I'll write a generic sum-digit lemma that handles any function g with bounded outputs, proving the extraction works for any k < n — this is standard induction and I only need to write it once. This proof chunk is substantial 150-250 lines with some trial-and-error , giving a 2× speedup, so it's worth doing if needed. | | | | Before diving in, I should measure where the actual bottleneck is. I'm running a few quick profiling experiments to compare the cost of evaluating the kernel on different inputs versus the overhead of traversing nodes. Testing with a trivial predicate that always returns true, then a leaf-only version with a bounded comparison, then the full current setup at scale, and finally trying the addDecl approach to see if that changes the profile. | | I've confirmed no parallelism with about 160 microseconds per leaf, so now I'll profile where the time is spent and test whether directly using addDecl with Eq.refl can avoid the double evaluation that decide might cause. | | bash | | | | cd /workspace/leanproject && head -n -3 /tmp/benchbase.lean /tmp/prof.lean && cat /tmp/prof.lean << 'EOF' | | def trivLeaf : Nat : Bool := true | | def c4Leaf x : Nat : Bool := Nat.ble c4 x 99999999999999 | | set option maxHeartbeats 0 in | | theorem p1 : allB trivLeaf 17 0 = true := by decide +kernel | | set option maxHeartbeats 0 in | | theorem p2 : allB c4Leaf 17 0 = true := by decide +kernel | | end D | | EOF | | pkill -STOP -x scan99; time timeout 280 lake env lean /tmp/prof.lean 2 &1 | grep -c error; pkill -CONT -x scan99; echo resumed | | | | | | 67 --- TOOL bash --- | | | | real 0m16.308s | | user 0m15.459s | | sys 0m1.918s | | | | 1 | | resumed | | | | | | 68 --- ASSISTANT --- | | I'm hitting an error with the p2 calculation—the bignum value for c4 at x=131071 is around 1.2e19, which exceeds the bound of 9.9e13, so I need to increase the bound to 2^80. Interestingly, the timing breakdown shows p1 took about 5.2 seconds for 131,072 trivial leaves while p2 failed quickly, suggesting roughly 40 microseconds per operation. | | | | The real bottleneck is kernel reduction overhead—each node unfold plus the arithmetic operations costs about 40 microseconds, which works out to roughly 7 microseconds per reduction. Even accounting for potential double-evaluation, the per-operation cost is still dominated by reduction overhead rather than the arithmetic itself. | | | | To optimize, I need to aggressively minimize reduction count: use single-evaluation declarations, increase node arity to 8-16 children to amortize the unfold cost, pack the c4 computation more efficiently through strips, and potentially combine the range check into the mask computation itself since strip boundaries guarantee c < W, eliminating redundant operations per leaf. | | | | For the arithmetic, I can precompute constants like 8W+1 per pair to reduce the v calculation from 3 operations to 2, and the mask test involves about 5 reductions total. With 64-strip linear recursion, the per-leaf overhead drops to roughly 10-11 reductions versus the current 26+, which should bring execution time down to around 30 microseconds per leaf—still constrained by that 3-7 microsecond kernel reduction cost, but acceptable for the overall runtime. | | | | Now I'm realizing the actual reduction count might be higher than I estimated because of how Bool.and unfolds in the core—each application involves delta reduction of the Bool.and definition, beta reduction, and then the matcher auxiliary constant, which compounds to about 4-5 reductions per .and call alone. | | | | Looking at a trivLeaf node specifically: the Nat.rec machinery adds roughly 3 reductions, Nat.add and Nat.pow have fast paths that cost 1 reduction each, Bool.and costs 4, and the trivLeaf delta itself is 1—totaling around 10 reductions per node, which translates to about 40 microseconds when evaluated twice, or roughly 2 microseconds per kernel reduction step. That's plausible given the overhead of cache lookups, instantiation, and allocation at each step. | | | | To push below that 2-microsecond threshold, I'd need to reduce the number of steps themselves, which means avoiding the conditional and Bool.and operations entirely—maybe using Nat arithmetic directly for control flow instead, like encoding test results as 0 or 1 and combining them arithmetically. | | | | Rather than Boolean early-outs, I could compute a single Nat "flag" for each candidate and sum the flags across the range, then check if the sum matches the expected count. This avoids Boolean logic entirely: each flag is just a masked bit extracted as a Nat pure arithmetic, no Bool.and . The sum tells me how many candidates passed a filter, but not which ones, so I'd need a two-phase approach where the first phase counts survivors and the second phase handles them. Exploring stronger single-mask approaches for filter1 — trying different moduli around 500K to reduce the pass rate further, but the tradeoff is that larger masks require expensive shift or division operations on massive GMP numbers, making the computational cost prohibitive. Trying different extraction approaches — bit shifting with masks is too expensive for large Q values, and precomputed chunk indexing adds too many reductions. Sticking with Q1=7425 where shifts are cheap enough at under a microsecond per operation. | | | | The realistic target is around 10-12 reductions per evaluation, which translates to 20-25 microseconds per single run — manageable for 90 million evaluations across a kernel. For survivors that need additional checks, I can use conditional branching on bit values with early-exit logic, adding just 2 reductions per operation. The tradeoff is proving soundness with packed c4-strips, which requires significant proof work, so I'm considering computing c4 incrementally instead to avoid that complexity. | | | | Rather than packing, I'll carry c4 values through the linear strip and update them using finite differences — maintaining the cubic difference d3 alongside d2 and d1, then updating all four with simple additions per iteration. | | | | The soundness proof is straightforward: I can verify the invariant that c equals c4 x and d3 equals the cubic difference at x using Pascal's identities and polynomial arithmetic, showing that c4 x+1 = c4 x + x+3 choose 3 . | | | | Now I'm exploring a state-carrying approach where instead of computing c4 x directly, I maintain a value v that tracks the difference, updating it by subtracting multiples of binomial coefficients at each step. Checking whether the kernel's whnf evaluation can handle the linear fuel loop without stack overflow — the recursive structure has the call nested inside applications, so whnf should iterate on the outermost term and avoid deep C++ recursion as long as things stay in tail position, though the conditional branching might complicate that. | | | | The elaborator had worse performance stack overflow at 100k , but the kernel path with linear recursion depth around 2200 should be manageable even if some recursion happens. Now I'm thinking about how to represent the state for the per-pair loop — a curried function taking fuel and the state tuple. | | | | Each iteration involves beta reductions, recursive unfolding, arithmetic operations, and a mask test, which adds up to roughly 15 reductions per step. At 2 microseconds per reduction, that's about 28 microseconds per iteration, scaling to around 42 minutes for 90 million iterations with the double-eval overhead. I'm considering whether I can optimize the modular arithmetic by tracking the value modulo 7425 incrementally rather than computing it fresh each time. | | | | The modulo operation itself is cheap on 40-bit values using GMP's fast path, so skipping it won't save much. For loop termination, I need to detect when the value underflows, which happens when c4 x exceeds the word boundary. I'm planning to compute an exact fuel bound at the pair level using a logarithmic formula and a runtime monotonicity check, then verify at the loop's end that the final value is small or that c4 at the next step would exceed the boundary. | | | | The formula for Xmax comes from log2 and gives me a linear fuel amount up to around 4400, though this wastes computation on values beyond the actual underflow point since they produce garbage results that need full verification anyway. | | | | The real issue is completeness: if the checker returns false on junk values beyond the underflow threshold, the whole approach fails. I need to either cap the fuel precisely at the underflow boundary or add a guard condition that validates each intermediate value before testing it. The simplest approach is comparing whether the value stays above zero after each subtraction, since the legitimate range for v is always at least 1. The soundness argument hinges on showing that once v drops below e3, all subsequent values exceed the threshold W. Since the invariant ties v directly to c4 x , when v becomes negative after subtraction, the recurrence relation forces c4 x+1 to jump above W, establishing monotonicity and proving early termination is safe. I'm setting fuel to a generous fixed value like 6000 so the guard stops iteration before exhaustion, making fuel decrement essentially free through Nat.rec on literals, and returning false on fuel exhaustion keeps the soundness argument straightforward. The x-loop itself is a linear recursion threading through state variables. | | | | Now I'm analyzing the per-iteration cost: the loop unfolds the recursion, applies beta reductions, checks the bit condition, evaluates the guard, and updates the state variables through arithmetic operations, totaling around 13-14 operations per iteration. | | | | Comparing approaches, the linear method at roughly 14 microseconds per iteration is actually faster than the tree approach which was estimated at 26, so even accounting for overhead this should handle 90 million iterations in reasonable time. I'm also reconsidering whether I need to update the difference variables every iteration or if I can optimize by computing them on demand, but the incremental updates via addition are already quite efficient. | | | | Now I'm formalizing the soundness proof for the new x-loop design by setting up an inductive invariant that relates the state variables to the current x value, establishing that the value v correctly tracks the formula 8· W − c4 x + 1 and that c4 x stays within bounds. | | | | Continuing with the key recurrence relations: I'm defining d3 x as the binomial coefficient C x+3,3 and d2 x as C x+2,2 , then expressing e3 and e2 in terms of these, and finally proving that the xrun function correctly maintains the invariant through each iteration with the crucial step that c4 increments by d3 x at each stage. So the recurrence relations all check out through Pascal's identity: c4 x+1 equals the sum of d3 x and c4 x , and similarly d3 x+1 follows from the binomial coefficient recurrence. For d2, I'm verifying that d2 x+1 = x+3 choose 2 decomposes correctly as x+2 choose 1 plus x+2 choose 2, which gives d2 x + x+2 , and e1 should consistently be 8 times x+1 choose 1. | | | | Now I'm setting e1 x = 8· x+2 with the update rule e1 += 8, giving e1 0 = 16. At the initial state x=0, I have v = 8W+1 with c4 0 = 0, and I'm computing the base values: e3 = 8·C 3,3 = 8, e2 = 8·C 2,2 = 8 since d2 0 = C 2,2 = 1, and e1 = 16. But when I check e3 1 = 8·C 4,3 = 32, the update rule e3 += e2 gives 8 + 8 = 16, which doesn't match—so I need to recalculate what d3 0 actually is using d3 x := x+3 choose 3. | | | | Now I'm verifying the recurrence relations: d3 x+1 = x+4 choose 3 equals x+3 choose 2 plus x+3 choose 3 by Pascal's identity, so d2 x = x+3 choose 2 with d2 0 = 3. This gives d3 1 = 1 + 3 = 4, which checks out. For d2, the recurrence d2 x+1 = x+4 choose 2 equals x+3 choose 1 plus x+3 choose 2, meaning d1 x = x+3, and d2 1 = 3 + 3 = 6 = C 4,2 as expected. I'm tracking e1 = 8· x+2 with the increment rule d1 += 1. | | | | Starting with x=0, the initial values are v = 8W+1, e3 = 8, e2 = 24, e1 = 24, all verified. The proof strategy uses Pascal's identity throughout—no ring arithmetic needed. For the loop structure, I'm testing the mask on the current value first, then applying guards and updates. The sqTest function is reused wholesale on the survivor path, which adds 4 operations due to redundant mask checking bit1 is already known to be 1 , but this costs only about 9.8% overhead and keeps the proofs simpler by treating the leaf semantics uniformly as a conditional on bit1. | | | | Both the mask miss and sqTest paths converge to proving the value isn't square. At the pair level, W = N − B and A = 8W+1 is computed per pair in 3 operations. Now I'm recounting the per-iteration cost: unfolding the recursion node, applying beta reductions across multiple arguments, computing the modulo operation, and shifting operations. Considering whether to use Nat.rec on the bit value to avoid the beq and cond overhead — it would save a couple reductions but makes the code less readable, so I'll stick with the straightforward conditional approach. I'm also thinking about whether to inline mask2 directly in the survivor check rather than keeping it separate, but the current structure with survivors feeding into sqTest is cleaner. My plan is to implement the linear loop for xrun while leaving the y and z trees unchanged. | | | | For the pair-level rewrite, I'm setting up the computation where ypair takes the input and calculates B = r8 + c6 y , then checks if B ≤ N . If not, I compute W = N − B and initialize A = 8W + 1 to feed into xrun with a fixed fuel of 6000 iterations. This fuel value covers W up to around 5.4e13, which is safe for the expected input range. The guard after testing each x checks whether e3 ≤ v to decide whether to continue or stop. I need to verify the edge case where W equals zero and check that the checker correctly rejects non-triangular numbers — the semantics should return false when W is triangular since that means the number isn't representable. Now I'm moving on to implement the xrun function with soundness verification, benchmark the performance again, and also set up the addDecl single-evaluation mechanism to confirm it actually achieves the 2× speedup we're targeting. I should also review scan99 around block 6 to see what's happening there. | | I've identified that the kernel costs about 2 microseconds per reduction, so I need to minimize reductions per leaf—I'm switching to a linear x-loop design using Pascal-identity incremental state with only additions per step. Now I'll verify the scan and implement it. | | bash | | | | tail -1 /tmp/scan99.err; cat /tmp/scan99.out | | | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | | | namespace D | | | | /- fast linear x-loop with incremental Pascal state. | | xrun fuel v e3 e2 e1 = true checks, starting at some x0 with | | v = 8 W - c4 x0 + 1 requires c4 x0 ≤ W | | e3 = 8 d3 x0, e2 = 8 d2 x0, e1 = 8 x0 + 3 | | that no x ≥ x0 and w give t2 w + c4 x = W . -/ | | | | def d3 x : Nat : Nat := x+3 .choose 3 | | def d2 x : Nat : Nat := x+3 .choose 2 | | | | def xstep v : Nat : Bool := | | cond Nat.beq Nat.land Nat.shiftRight M1 Nat.mod v Q1 1 0 | | true | | sqTest v | | | | def xrun : Nat → Nat → Nat → Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Nat → Nat → Nat → Bool | | fun = false | | fun ih v e3 e2 e1 = | | xstep v .and | | cond Nat.ble e3 v | | ih Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true | | fuel | | | | theorem xstep sound {v : Nat} h : xstep v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | cases hb : Nat.beq Nat.land Nat.shiftRight M1 Nat.mod v Q1 1 0 with | | | true = | | have m1 := mask1 all j | | rw hj at m1 | | rw maskBit at m1 | | -- m1 : Nat.beq Nat.land Nat.shiftRight M1 v % Q1 1 1 = true | | have hb' : Nat.beq Nat.land Nat.shiftRight M1 v % Q1 1 0 = true := hb | | rw Nat.beq eq at m1 hb' | | omega | | | false = | | rw xstep, hb, cond false at h | | exact sqTest sound h j hj | | | | -- key Pascal identities | | theorem c4 succ x : Nat : c4 x+1 = c4 x + d3 x := by | | rw ← choose4 eq, ← choose4 eq, d3 | | have : x + 1 + 3 = x + 3 + 1 := by omega | | rw this, Nat.choose succ succ x+3 3 | | omega | | | | theorem d3 succ x : Nat : d3 x+1 = d3 x + d2 x := by | | rw d3, d3, d2 | | have : x + 1 + 3 = x + 3 + 1 := by omega | | rw this, Nat.choose succ succ x+3 2 | | omega | | | | theorem d2 succ x : Nat : d2 x+1 = d2 x + x+3 := by | | rw d2, d2 | | have : x + 1 + 3 = x + 3 + 1 := by omega | | rw this, Nat.choose succ succ x+3 1, Nat.choose one right | | omega | | | | theorem xrun sound {W : Nat} : ∀ fuel x0 : Nat , | | c4 x0 ≤ W → | | xrun fuel 8 W - c4 x0 + 1 8 d3 x0 8 d2 x0 8 x0+3 = true → | | ∀ w x, x0 ≤ x → t2 w + c4 x ≠ W := by | | intro fuel | | induction fuel with | | | zero = | | intro x0 h | | exact absurd h by rw xrun ; simp | | | succ f ih = | | intro x0 hc4 h w x hx heq | | have hrun : xrun f+1 8 W - c4 x0 + 1 8 d3 x0 8 d2 x0 8 x0+3 = true := h | | rw show xrun f+1 = fun v e3 e2 e1 = | | xstep v .and | | cond Nat.ble e3 v | | xrun f Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true from rfl at hrun | | simp only Bool.and eq true at hrun | | obtain ⟨hstep, hrest⟩ := hrun | | rcases Nat.eq or lt of le hx with rfl | hlt | | · -- x = x0 : current leaf | | have hv : 2 w+3 2 w+3 = 8 W - c4 x0 + 1 := by | | have h1 := eight t2 w | | have : t2 w = W - c4 x0 := by omega | | omega | | exact xstep sound hstep 2 w+3 hv | | · -- x x0 : recurse or early-stop | | cases hg : Nat.ble 8 d3 x0 8 W - c4 x0 + 1 with | | | true = | | rw hg, cond true at hrest | | rw Nat.ble eq at hg | | -- c4 x0+1 ≤ W | | have hc4s : c4 x0+1 ≤ W := by | | have := c4 succ x0 | | omega | | have ev : Nat.sub 8 W - c4 x0 + 1 8 d3 x0 = 8 W - c4 x0+1 + 1 := by | | have := c4 succ x0 | | simp only sub eqn | | omega | | have e3' : Nat.add 8 d3 x0 8 d2 x0 = 8 d3 x0+1 := by | | have := d3 succ x0 | | simp only add eqn | | omega | | have e2' : Nat.add 8 d2 x0 8 x0+3 = 8 d2 x0+1 := by | | have := d2 succ x0 | | simp only add eqn | | omega | | have e1' : Nat.add 8 x0+3 8 = 8 x0+1 +3 := by | | simp only add eqn | | omega | | rw ev, e3', e2', e1' at hrest | | exact ih x0+1 hc4s hrest w x hlt heq | | | false = | | -- early stop: c4 x0+1 W, so all x x0 fail | | rw ← Nat.ble eq at hc4 ⊢ <; try skip | | have hgt : ¬ 8 d3 x0 ≤ 8 W - c4 x0 + 1 := by | | rw ← Nat.ble eq, hg ; simp | | have hc4x : W < c4 x := by | | have hs := c4 succ x0 | | have hmono : c4 x0+1 ≤ c4 x := c4 mono by omega | | have hcle : c4 x0 ≤ W := by rwa Nat.ble eq at hc4 | | omega | | have ht := t2 ge one w | | omega | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A8 | head -40 | | | | | | 68 --- TOOL bash --- | | block 5/24 done marks=158574942909 zeros=0 | | | | | | 68 --- TOOL bash --- | | Dev/Checker.lean:423:2: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | d ≥ 0 | | c ≥ 0 | | b ≥ 0 | | b - d ≥ 1 | | a ≥ 0 | | where | | a := ↑x | | -- | | Dev/Checker.lean:429:2: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | d ≥ 0 | | c ≥ 0 | | b ≥ 0 | | b - d ≥ 1 | | a ≥ 0 | | where | | a := ↑x | | -- | | Dev/Checker.lean:435:2: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | c ≥ 0 | | b ≥ 0 | | b - c ≥ 1 | | a ≥ 0 | | where | | a := ↑x | | b := ↑ x + 3 .choose 2 | | -- | | Dev/Checker.lean:491:12: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | ?m.604 ≤ ?m.605 | | in the target expression | | False | | | | case succ.inr.false | | W f : ℕ | | ih : | | ∀ x0 : ℕ , | | | | | | 69 --- ASSISTANT --- | | I'm working through some rewrite errors with the c4 succ lemma—the goal after applying choose succ succ doesn't match what I expected, and I'm trying to figure out how the choose4 eq rewrite should work in reverse to transform c4 x+1 into the binomial coefficient form. The rewrite might have failed silently because Lean's normalization of addition expressions doesn't match my pattern — x+1+3 parses differently than x+3+1 even though they're equal. The constraint b - d ≥ 1 appearing in the error suggests the goal after rewrites involves a subtraction between choose terms, which omega can't handle directly since it treats them as atomic values. | | | | Rather than wrestling with the rewrite, I should prove the three identities more directly using Nat.choose symm diff or similar lemmas. I also spotted a bug at line 491 where I tried to rewrite the goal itself as a Bool equation — that's nonsense since the goal is a proposition, not a boolean. I need to delete that line and just use the hypothesis hc4 directly as a constraint. Let me probe the actual goal state for c4 succ to see what I'm working with. | | bash | | | | cd /workspace/leanproject && cat /tmp/p3.lean << 'EOF' | | import Mathlib | | check @Nat.choose succ succ | | check @Nat.choose succ succ' | | example x : Nat : x+4 .choose 4 = x+3 .choose 4 + x+3 .choose 3 := by | | rw show x+4 = x+3 +1 from rfl, Nat.choose succ succ x+3 3 | | omega | | EOF | | timeout 200 lake env lean /tmp/p3.lean 2 &1 | head | | | | | | 69 --- TOOL bash --- | | Nat.choose succ succ : ∀ n k : ℕ , n.succ.choose k.succ = n.choose k + n.choose k.succ | | Nat.choose succ succ' : ∀ n k : ℕ , n + 1 .choose k + 1 = n.choose k + n.choose k + 1 | | /tmp/p3.lean:6:2: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | c ≥ 0 | | b ≥ 0 | | a ≥ 0 | | a - c ≥ 1 | | where | | a := ↑ x + 3 .choose 4 | | | | | | 70 --- ASSISTANT --- | | The rewrite tactic produced an unexpected form where it's treating x+3 .choose 3.succ and x+3 .choose 4 as syntactically distinct atoms, even though they should be equivalent—the issue is that one uses the successor function notation while the other uses the literal numeral, so omega isn't recognizing them as the same thing. | | | | I should try using Nat.choose succ succ' instead and then apply norm num to normalize the successor expressions into their literal forms, which should let omega close the goal by commutativity. | | bash | | | | cd /workspace/leanproject && cat /tmp/p4.lean << 'EOF' | | import Mathlib | | example x : Nat : x+4 .choose 4 = x+3 .choose 4 + x+3 .choose 3 := by | | rw show x+4 = x+3 +1 from rfl, Nat.choose succ succ' x+3 3 | | norm num | | omega | | example x : Nat : x+4 .choose 2 = x+3 .choose 2 + x+3 := by | | rw show x+4 = x+3 +1 from rfl, Nat.choose succ succ' x+3 1, Nat.choose one right | | norm num | | omega | | EOF | | timeout 200 lake env lean /tmp/p4.lean 2 &1 | head | | | | | | 70 --- TOOL bash --- | | | | 71 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | old = '''theorem c4 succ x : Nat : c4 x+1 = c4 x + d3 x := by | | rw ← choose4 eq, ← choose4 eq, d3 | | have : x + 1 + 3 = x + 3 + 1 := by omega | | rw this, Nat.choose succ succ x+3 3 | | omega | | | | theorem d3 succ x : Nat : d3 x+1 = d3 x + d2 x := by | | rw d3, d3, d2 | | have : x + 1 + 3 = x + 3 + 1 := by omega | | rw this, Nat.choose succ succ x+3 2 | | omega | | | | theorem d2 succ x : Nat : d2 x+1 = d2 x + x+3 := by | | rw d2, d2 | | have : x + 1 + 3 = x + 3 + 1 := by omega | | rw this, Nat.choose succ succ x+3 1, Nat.choose one right | | omega''' | | new = '''theorem c4 succ x : Nat : c4 x+1 = c4 x + d3 x := by | | rw ← choose4 eq, ← choose4 eq, d3 | | rw show x + 1 + 3 = x + 3 + 1 from by omega, Nat.choose succ succ' x+3 3 | | norm num | | omega | | | | theorem d3 succ x : Nat : d3 x+1 = d3 x + d2 x := by | | rw d3, d3, d2 | | rw show x + 1 + 3 = x + 3 + 1 from by omega, Nat.choose succ succ' x+3 2 | | norm num | | omega | | | | theorem d2 succ x : Nat : d2 x+1 = d2 x + x+3 := by | | rw d2, d2 | | rw show x + 1 + 3 = x + 3 + 1 from by omega, Nat.choose succ succ' x+3 1, | | Nat.choose one right | | norm num | | omega''' | | assert old in src; src = src.replace old, new | | old = ''' | false = | | -- early stop: c4 x0+1 W, so all x x0 fail | | rw ← Nat.ble eq at hc4 ⊢ <; try skip | | have hgt : ¬ 8 d3 x0 ≤ 8 W - c4 x0 + 1 := by | | rw ← Nat.ble eq, hg ; simp | | have hc4x : W < c4 x := by | | have hs := c4 succ x0 | | have hmono : c4 x0+1 ≤ c4 x := c4 mono by omega | | have hcle : c4 x0 ≤ W := by rwa Nat.ble eq at hc4 | | omega | | have ht := t2 ge one w | | omega''' | | new = ''' | false = | | -- early stop: c4 x0+1 W, so all x x0 fail | | have hgt : ¬ 8 d3 x0 ≤ 8 W - c4 x0 + 1 := by | | rw ← Nat.ble eq, hg ; simp | | have hs := c4 succ x0 | | have hmono : c4 x0+1 ≤ c4 x := c4 mono by omega | | have ht := t2 ge one w | | omega''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A8 | head -40 | | | | | | 71 --- TOOL bash --- | | | | 72 --- ASSISTANT --- | | I'm switching the pair-level verification to use xrun instead of xtreeOK, defining a check function that runs the solver with specific parameters and then proving its soundness by appealing to the underlying xrun sound theorem. I need to verify the fuel bound works correctly—with 6000 fuel, the guard condition triggers before exhaustion since W must stay below roughly 5.4e13. The kernel handles the literal fuel unfolding efficiently through the successor chain. Now I'll update leafY to use xcheck and re-benchmark the performance. | | xrun compiles successfully. Now I'll integrate it at the pair level to replace the balanced-tree x-loop and re-benchmark. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | add = ''' | | | | namespace D | | | | /-- full x-check via the linear incremental loop. -/ | | def xcheck W : Nat : Bool := xrun 6000 Nat.add Nat.mul 8 W 1 8 24 24 | | | | theorem xcheck sound {W : Nat} h : xcheck W = true : ∀ w x, t2 w + c4 x ≠ W := by | | have h0 : c4 0 = 0 := rfl | | have hv : Nat.add Nat.mul 8 W 1 = 8 W - c4 0 + 1 := by | | simp only add eqn, mul eqn, h0 | | have hd3 : 8 : Nat = 8 d3 0 := by norm num d3 | | have hd2 : 24 : Nat = 8 d2 0 := by norm num d2 ; rfl | | have he1 : 24 : Nat = 8 0+3 := by norm num | | rw xcheck, hv, hd3, hd2, he1 at h | | intro w x | | exact xrun sound 6000 0 by simp h0 h w x Nat.zero le x | | | | /-- new leafY using the fast x loop. -/ | | def leafY2 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xcheck Nat.sub N b | | | | theorem leafY2 sound {N r8 y : Nat} h : leafY2 N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp | | simp only leafY2, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xcheck sound h w x this | | | | def ytreeOK2 N fy r8 : Nat : Bool := | | allB leafY2 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | theorem ytreeOK2 sound {N fy r8 : Nat} h : ytreeOK2 N fy r8 = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | simp only ytreeOK2 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY2 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | def leafZ2 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true ytreeOK2 N fy r8 | | | | theorem leafZ2 sound {N fy z : Nat} h : leafZ2 N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ2, hb, cond false at h | | exact ytreeOK2 sound h w x y heq | | | | theorem master2 {N fy fz : Nat} | | h : allB leafZ2 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ2 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | ''' | | src += add | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A8 | head -30 | | | | | | 72 --- TOOL bash --- | | Dev/Checker.lean:509:58: error: unsolved goals | | W : ℕ | | h : xcheck W = true | | h0 : c4 0 = 0 | | ⊢ 8 W + 1 = 8 W - 0 + 1 | | Dev/Checker.lean:512:56: error: No goals to be solved | | Dev/Checker.lean:514:28: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | 24 | | in the target expression | | xrun 6000 8 d3 0 W - c4 0 + 1 8 d3 0 8 d2 0 8 d2 0 = true | | | | W : ℕ | | h : xrun 6000 8 d3 0 W - c4 0 + 1 8 d3 0 8 d2 0 8 d2 0 = true | | h0 : c4 0 = 0 | | hv : Nat.mul 8 W .add 1 = 8 W - c4 0 + 1 | | | | | | 73 --- ASSISTANT --- | | I need to fix the rewriting order to avoid unintended replacements when converting multiple instances of the same literal value. I'm combining the conversions into a single statement that applies all the transformations at once, then using normalization tactics to verify both sides evaluate correctly. Establishing the remaining equalities with norm num to handle the arithmetic, then rewriting with all four equations and applying the hypothesis to close the goal. Now I need to unfold the xcheck definition in the hypothesis before applying exact, since h is still in its checked form rather than expanded to the xrun call that matches the goal. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | old = '''theorem xcheck sound {W : Nat} h : xcheck W = true : ∀ w x, t2 w + c4 x ≠ W := by | | have h0 : c4 0 = 0 := rfl | | have hv : Nat.add Nat.mul 8 W 1 = 8 W - c4 0 + 1 := by | | simp only add eqn, mul eqn, h0 | | have hd3 : 8 : Nat = 8 d3 0 := by norm num d3 | | have hd2 : 24 : Nat = 8 d2 0 := by norm num d2 ; rfl | | have he1 : 24 : Nat = 8 0+3 := by norm num | | rw xcheck, hv, hd3, hd2, he1 at h | | intro w x | | exact xrun sound 6000 0 by simp h0 h w x Nat.zero le x ''' | | new = '''theorem xcheck sound {W : Nat} h : xcheck W = true : ∀ w x, t2 w + c4 x ≠ W := by | | intro w x | | rw xcheck at h | | refine xrun sound 6000 0 by simp show c4 0 = 0 from rfl ? w x Nat.zero le x | | have e1 : 8 W - c4 0 + 1 = Nat.add Nat.mul 8 W 1 := by | | simp show c4 0 = 0 from rfl | | have e2 : 8 d3 0 = 8 := rfl | | have e3 : 8 d2 0 = 24 := rfl | | have e4 : 8 0+3 = 24 := rfl | | rw e1, e2, e3, e4 | | exact h''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A8 | head -30 | | | | | | 73 --- TOOL bash --- | | | | 74 --- ASSISTANT --- | | Now I'm benchmarking the optimized fast path by running xcheck across roughly 32 W values near 9e11, which generates about 69k x-iterations total. I also need to verify correctness by confirming that xcheck returns false when testing a W that has a valid representation, like the one constructed from t2 5 and c4 7 . | | bash | | | | cd /workspace/leanproject && cat /tmp/bench2.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | EOF | | sed '1,2d' Dev/Checker.lean /tmp/bench2.lean | | cat /tmp/bench2.lean << 'EOF' | | | | namespace D | | def benchP2 p : Nat : Bool := | | let b := xcheck Nat.sub 908070605043 Nat.mul 977 p | | b.or Bool.not b | | set option maxHeartbeats 0 in | | theorem bb : allB benchP2 5 0 = true := by decide +kernel | | -- sanity: a W with a representation must fail: W = t2 3 + c4 5 = 10+... t2 3 = 10? 3+2 3+1 /2=10; c4 5 = 5 6 7 8/24=70; W=80 | | theorem bfail : xcheck 80 = false := by decide +kernel | | end D | | EOF | | pkill -STOP -x scan99; time timeout 280 lake env lean /tmp/bench2.lean 2 &1 | grep -cE "error"; pkill -CONT -x scan99; echo resumed | | | | | | 74 --- TOOL bash --- | | | | real 1m43.600s | | user 1m41.111s | | sys 0m2.525s | | | | 0 | | resumed | | | | | | 75 --- ASSISTANT --- | | I'm seeing a massive performance regression in the xrun kernel evaluation — 1.3 milliseconds per iteration compared to just 160 microseconds for the tree version, which suggests something pathological is happening in how the recursive structure is being evaluated. The motive function for the natural number recursion is taking on a complex type with multiple Nat arguments and a Bool return, and I'm wondering what's causing this blowup. | | | | Looking at how the closure gets constructed in the fold — the inductive hypothesis ih is built with Nat.rec applied to fuel-1 , then the body applies ih to four arguments while also checking conditions with Bool.and . The key question is whether Bool.and is forcing evaluation of both branches even when the first argument is false, which would mean the recursive call gets evaluated unnecessarily. Lean's definition of Bool.and is lazy in the second argument, so that shouldn't be the culprit. The conditional cond also evaluates lazily based on the condition result. But the real issue might be how the expression arguments like Nat.sub v e3 are being substituted and then re-evaluated at each recursion level — even though they're literals, the repeated evaluation overhead could be adding up across thousands of iterations. | | | | Now looking at the fuel and iteration counts: with fuel 6000, the early stopping happens through the guard condition rather than exhausting fuel, so we get around 2160 iterations before the loop terminates when the bound is exceeded. That matches the expected value. But the performance is still puzzling — roughly 650 reductions per iteration at 2 microseconds each suggests something quadratic is happening, possibly from how Nat.rec unfolds and reconstructs the motive lambda at each recursion level. The 25× slowdown from the double evaluation is suspicious — I'm wondering if the kernel lacks an optimized path for Nat.rec when the major premise is a GMP literal, forcing it to convert lit 6000 into a full successor chain one layer at a time. Even though each unfold should be O 1 , repeatedly hashing the GMP number at each level could add up. Another angle: xstep pulls in sqTest and mask constants, which might be getting reconstructed or re-evaluated in ways I haven't accounted for. I should set up a benchmark to measure the actual cost: run xrun with 2160 iterations and expect around 0.12 seconds based on the calculation, then create a stripped-down version without the xstep logic to isolate where the overhead is coming from. | | Unexpectedly slow 1.3ms/x . Something pathological — let me bisect components: | | bash | | | | cd /workspace/leanproject && cat /tmp/bench3.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | EOF | | sed '1,2d' Dev/Checker.lean /tmp/bench3.lean | | cat /tmp/bench3.lean << 'EOF' | | | | namespace D | | -- stripped loop: no xstep, just state updates + guard | | def xrunStrip : Nat → Nat → Nat → Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Nat → Nat → Nat → Bool | | fun = false | | fun ih v e3 e2 e1 = | | cond Nat.ble e3 v | | ih Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true | | fuel | | set option maxHeartbeats 0 in | | theorem bs : xrunStrip 6000 Nat.add Nat.mul 8 908070605043 1 8 24 24 = true := by decide +kernel | | end D | | EOF | | pkill -STOP -x scan99; time timeout 280 lake env lean /tmp/bench3.lean 2 &1 | grep -cE "error"; pkill -CONT -x scan99 | | | | | | 75 --- TOOL bash --- | | | | real 0m14.115s | | user 0m12.999s | | sys 0m2.183s | | | | 0 | | | | | | 76 --- ASSISTANT --- | | The loop itself is the bottleneck, not the xstep function—stripping it down saves about 2.5 seconds across 2160 iterations, which works out to roughly 1.2 milliseconds per iteration. Each iteration involves around 600 reduction-equivalents from the guard and update operations, suggesting quadratic behavior where the cost scales with how much fuel remains in the recursion. | | | | When I trace through how xrunStrip unfolds, the kernel reduces the major premise the fuel literal , then applies the minor premise lambda to construct the recursive call. Each step should only take 15-20 reductions with small instantiations, which doesn't account for the 600 reductions I'm seeing—unless the kernel's weak-head-normal-form evaluation isn't caching or sharing something it should be. | | | | The culprit might be that unevaluated expressions like Nat.add e3 prev e2 prev get passed down through the recursion without being cached. When ble forces e3 to weak-head-normal-form at each level, it has to walk the entire accumulated chain of additions from previous levels. If these intermediate results aren't cached, then at recursion depth k, forcing e3 costs O k work, leading to quadratic blowup overall. The kernel's whnf cache could theoretically make this linear if it hits on previously forced subexpressions, but instantiation creates fresh expression nodes during beta reduction, so those new nodes won't match cached entries and force re-evaluation of the entire chain at each level. The whnf cache in Lean 4 uses object pointers as keys, so when both child arguments are already cached as literals, the addition can resolve in constant time through a fast-path that avoids recomputation — this should give us linear overall complexity. | | | | But I'm wondering if the cache isn't actually being used for these intermediate applications, or if it's getting cleared between calls, or if the Nat.add fast-path is calling whnf without leveraging the cache properly. There might also be multiple separate caches like whnf core that aren't coordinating. The empirical behavior looked quadratic-ish, so let me test that hypothesis directly by comparing performance across different input sizes to see if the cost scales quadratically or linearly. | | | | The real issue might be that I'm chaining unevaluated arguments through the recursion — I should force each state component to be evaluated inside the step function so that what gets passed down is already a concrete value. But the kernel uses call-by-name evaluation and there's no seq primitive to force evaluation. The guard condition does force e3 and v at each level, but e2 and e1 just accumulate without being evaluated until the guard finally needs e3, which means the entire chain of e2 computations builds up unevaluated. | | | | If weak head normal form caching isn't working effectively for these intermediate values, then forcing e3 at depth k requires walking back through the entire e2 chain, which itself requires walking through e1 — this creates the quadratic behavior I'm seeing. The kernel probably isn't caching these weak head normal forms, possibly because the fast-path for extracting natural number literals recurses without caching. | | | | The fix is to force evaluation through the control flow itself by making every state variable pass through a comparison before recursing, essentially chaining guards together so nothing stays unevaluated. The real issue is that without caching, guards at every level don't actually prevent chains from reforming—the nodes themselves never get replaced in the term structure. The only way to fix this is to ensure the kernel receives already-literal arguments by forcing and rebuilding within the recursion, but that's impossible in pure call-by-name without some form of caching. I'm wondering if the kernel might actually be doing some caching that I'm not accounting for. | | | | Let me test the quadratic hypothesis empirically first, then try the guard-chain variant to see if the kernel's weak-head-normal-form actually replaces arguments in the parent application during evaluation—some evaluators do use memoization via update. Alternatively, I could sidestep call-by-name entirely and go back to the balanced tree structure, which showed linear behavior before. With that approach, tree leaves recompute directly from the base index without chained state, and the tree only passes down the base index itself, keeping the chain depth proportional to tree depth. | | | | The leaf computation costs about 25-27 reductions including node overhead, which measured around 160 microseconds with double evaluation included—so roughly 80 microseconds for a single evaluation, or about 3 microseconds per reduction. I can cut this down by using the single-eval addDecl trick for a 2× speedup, then optimize the node overhead further. | | | | I'm considering whether to pass a stride literal down the tree instead of computing powers of 2 at each node, or switch to an explicit interval midpoint representation—but that would require generating a massive file for 100 million leaves, which isn't practical. A simpler win is folding the four additions in the leaf computation: instead of computing x+1, x+2, x+3 separately, I can combine them into a single expression like x² + 3x. | | | | Now I'm optimizing the arithmetic itself—computing t = x² + 3x in just 2 operations one multiplication and one addition , then deriving c4 from that in 3 more operations, bringing the total down to 5 instead of 7. The rest of the leaf work computing v, taking modulo 7425, bit testing, and checking conditions adds up to about 20 operations per node, which at roughly 40-50 microseconds per leaf means processing 100 million leaves would take around 83 minutes—acceptable for this use case. | | | | I'm also exploring a hybrid approach where the tree descends only to strips of 32 leaves, then runs a short linear pass within each strip using chained quadratic evaluation, but the math shows this adds about 15 extra operations per leaf compared to the current leaf-local recomputation strategy of 13, so it's not worth pursuing. | | | | I'm also checking whether replacing the .and matcher chains with explicit conditional logic would save anything—turns out the cost is the same—and I need to verify whether the decide +kernel command is double-evaluating by comparing it against a direct run cmd-addDecl test. | | | | Now I want to run three quick benchmarks: test the quadratic scaling hypothesis by running xrunStrip at double the current threshold to see if it hits 4× time as expected, measure the addDecl trick timing, and benchmark the optimized-leaf tree approach. | | I've identified that the linear loop exhibits quadratic behavior due to the kernel's call-by-name evaluation repeatedly traversing unevaluated argument chains without memoization across state updates. Next, I'll test whether a balanced tree combined with the addDecl single-evaluation approach resolves this. | | bash | | | | cd /workspace/leanproject && cat /tmp/bench4.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | namespace D | | def xrunStrip : Nat → Nat → Nat → Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Nat → Nat → Nat → Bool | | fun = false | | fun ih v e3 e2 e1 = | | cond Nat.ble e3 v | | ih Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true | | fuel | | set option maxHeartbeats 0 in | | theorem bs2 : xrunStrip 12000 Nat.add Nat.mul 8 14529129680688 1 8 24 24 = true := by decide +kernel | | end D | | EOF | | pkill -STOP -x scan99; time timeout 280 lake env lean /tmp/bench4.lean 2 &1 | grep -cE "error"; pkill -CONT -x scan99 | | | | | | 76 --- TOOL bash --- | | | | real 0m7.375s | | user 0m5.325s | | sys 0m1.874s | | | | 0 | | | | | | 77 --- ASSISTANT --- | | I'm noticing something odd with the timing—the iteration count came out to around 4320, which is double what I expected, yet the execution time seems inconsistent with the baseline overhead. The framework compilation alone was taking about 10.5 seconds, but this particular file doesn't include the full framework, just minimal definitions, so the baseline should be closer to 4.5 seconds for imports. That would put the actual cost of running 4320 iterations at roughly 0.8 seconds, which feels off. | | | | Looking back at the earlier benchmark, I had 2160 iterations taking 2.5 seconds with the full framework included—that's about 1.2 milliseconds per iteration. But now with 4320 iterations in 0.8 seconds, I'm getting 0.18 milliseconds per iteration, which is way faster and doesn't follow a quadratic pattern at all. The discrepancy suggests my baseline attribution might be wrong, or the framework compilation time wasn't properly isolated. I need to run clean measurements: time an import-only file, then run the same file with small fuel 100 iterations to establish a true baseline, then again with 12000 iterations, all with pauses between runs to avoid caching effects. | | Confusing timings — need proper baselines: | | bash | | | | cd /workspace/leanproject && sed 's/12000 Nat.add Nat.mul 8 14529129680688 1 /100 Nat.add Nat.mul 8 100000 1 /' /tmp/bench4.lean /tmp/bench4a.lean && pkill -STOP -x scan99; echo "== baseline tiny fuel "; time timeout 280 lake env lean /tmp/bench4a.lean 2 &1 | grep -cE "error"; echo "== fuel 12000 W=1.45e13"; time timeout 280 lake env lean /tmp/bench4.lean 2 &1 | grep -cE "error"; pkill -CONT -x scan99 | | | | | | 77 --- TOOL bash --- | | | | real 0m6.720s | | user 0m4.731s | | sys 0m1.710s | | | | real 0m6.706s | | user 0m4.834s | | sys 0m1.810s | | | | == baseline tiny fuel | | 0 | | == fuel 12000 W=1.45e13 | | 0 | | | | | | 78 --- ASSISTANT --- | | So xrunStrip is incredibly fast at around 25 microseconds per iteration, which means the slowness in bench3 must be coming from somewhere else — likely the framework overhead and the massive fuel value. When I compare bench3 with the full framework and 9e11 fuel taking 13 seconds against bench4 without the framework at 4.8 seconds, the framework compilation alone is eating up roughly 8 seconds of that time. | | | | Now looking at bench2's 101-second runtime, that's coming from benchP2 which runs xcheck with xstep over 32 pairs, totaling about 69k full iterations — which works out to roughly 1.27 milliseconds per iteration with xstep included. So xstep is the expensive operation here. Breaking down xstep: it does a shift right on a 7425-bit number M1 by some amount, then a bitwise AND and equality check — all of which should be trivial. The real cost comes from the 9.8% of cases that call sqTest, which involves shifting larger numbers and running Newton's method for square root approximation. Newton converges in about 6-8 iterations before stopping, and even accounting for the bracket operation on 0.18% of cases, this should only add negligible overhead. | | | | Wait, but there's something about how Nat.mod is being handled — Q1 is defined as a constant, and the kernel's fast-path for Nat.mod requires both arguments to be literals, which should make it O 1 after unfolding. | | | | Actually, I'm realizing the kernel fast-paths might not be reducing the arguments to weak head normal form first — they just check if both args are already literals. If Q1 is a constant definition rather than a literal, the fast-path fails and it falls back to unfolding the recursive definition of Nat.mod, which is just repeated subtraction. For v around 7 trillion, that's potentially hundreds of millions of subtraction steps, which would be catastrophically slow. | | | | But we're seeing it complete, so the fast-path must be working. Let me think about this differently — maybe the kernel does WHNF the arguments before calling extension operations. I should empirically test by benchmarking with different mask combinations to isolate where the slowdown is actually coming from, and also check if the Bool.and matcher in the xrun loop is the culprit. | | | | Now I'm wondering about the newton function in Racket — it uses Nat.pow with Nat.log2 to compute the seed, and I need to verify if Nat.log2 is kernel-accelerated or if it's defined recursively. If it's a well-founded recursive definition, the kernel unfolding could be problematic. | | | | The issue is that Acc.rec used for well-founded recursion contains proof-irrelevant arguments that don't reduce in the kernel, which would cause decide to get stuck when trying to reduce Nat.log2 . But my tests passed, including the bracket paths through newton , which means log2 actually did reduce successfully. This suggests Nat.log2 might be implemented structurally with fuel rather than as a pure well-founded definition, so let me check the actual Lean 4 core implementation. | | | | Now I'm setting up an empirical bisection of the xstep function to isolate the performance bottleneck: I'll test variants ranging from always returning true, to adding just the mask tests, then both masks, then the full bracket logic replaced with true, and finally the complete version. I'll run these as separate theorems on the same 32 benchmark pairs to measure the time increments and identify which component is causing the slowdown. | | The bare loop is FAST — the cost is inside xstep . Bisect its components: | | bash | | | | cd /workspace/leanproject && cat /tmp/bench5.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | EOF | | sed '1,2d' Dev/Checker.lean /tmp/bench5.lean | | cat /tmp/bench5.lean << 'EOF' | | | | namespace D | | -- variant loops with different step bodies | | def mkrun step : Nat → Bool : Nat → Nat → Nat → Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Nat → Nat → Nat → Bool | | fun = false | | fun ih v e3 e2 e1 = | | step v .and | | cond Nat.ble e3 v | | ih Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true | | fuel | | | | def stepTrue : Nat : Bool := true | | def stepM1 v : Nat : Bool := | | cond Nat.beq Nat.land Nat.shiftRight M1 Nat.mod v Q1 1 0 true true | | def stepM12 v : Nat : Bool := | | cond Nat.beq Nat.land Nat.shiftRight M1 Nat.mod v Q1 1 0 true | | cond Nat.beq Nat.land Nat.shiftRight M2 Nat.mod v Q2 1 0 true true | | def stepM123 v : Nat : Bool := | | cond Nat.beq Nat.land Nat.shiftRight M1 Nat.mod v Q1 1 0 true | | cond Nat.beq Nat.land Nat.shiftRight M2 Nat.mod v Q2 1 0 true | | cond Nat.beq Nat.land Nat.shiftRight M3 Nat.mod v Q3 1 0 true true | | | | def benchWith step : Nat → Bool p : Nat : Bool := | | let b := mkrun step 6000 Nat.add Nat.mul 8 Nat.sub 908070605043 Nat.mul 977 p 1 8 24 24 | | b.or Bool.not b | | | | set option maxHeartbeats 0 in | | theorem bT : allB benchWith stepTrue 5 0 = true := by decide +kernel | | EOF | | cp /tmp/bench5.lean /tmp/bench5a.lean && echo 'set option maxHeartbeats 0 in | | theorem bM1 : allB benchWith stepM1 5 0 = true := by decide +kernel' /tmp/bench5a.lean | | cp /tmp/bench5a.lean /tmp/bench5b.lean && echo 'set option maxHeartbeats 0 in | | theorem bM12 : allB benchWith stepM12 5 0 = true := by decide +kernel | | set option maxHeartbeats 0 in | | theorem bM123 : allB benchWith stepM123 5 0 = true := by decide +kernel' /tmp/bench5b.lean | | pkill -STOP -x scan99 | | echo "== stepTrue only"; time timeout 280 lake env lean /tmp/bench5.lean 2 &1 | grep -cE "error" | | echo "== + stepM1"; time timeout 280 lake env lean /tmp/bench5a.lean 2 &1 | grep -cE "error" | | echo "== + M12 + M123"; time timeout 280 lake env lean /tmp/bench5b.lean 2 &1 | grep -cE "error" | | pkill -CONT -x scan99 | | | | | | 78 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 79 --- ASSISTANT --- | | bash | | | | pkill -CONT -x scan99; sleep 2; tail -1 /tmp/scan99.err | | | | | | 79 --- TOOL bash --- | | block 6/24 done marks=159205887297 zeros=0 | | | | | | 80 --- ASSISTANT --- | | The benchmark timed out at 300 seconds, so I need to run each variant individually in the background with separate timing measurements. I'll use a nohup script to run them sequentially while keeping scan99 paused during the tests, though I need to resume it afterward since it still has about 18 blocks remaining. Running under contention will skew the results by roughly 15%, but that's acceptable given the constraints. | | | | I'm writing a script that iterates through each benchmark file and uses the time command to measure how long each one takes to run. | | bash | | | | cd /workspace/leanproject && cat /tmp/runbench.sh << 'EOF' | | /bin/bash | | for f in bench5 bench5a bench5b; do | | echo "=== $f" /tmp/bench.log | | /usr/bin/time -v timeout 600 lake env lean /tmp/$f.lean /tmp/bench.log 2 &1 | | echo "exit=$?" /tmp/bench.log | | done | | echo ALLDONE /tmp/bench.log | | EOF | | chmod +x /tmp/runbench.sh && rm -f /tmp/bench.log && nohup /tmp/runbench.sh /dev/null 2 &1 & echo started | | | | | | 80 --- TOOL bash --- | | started | | | | | | 81 --- ASSISTANT --- | | bash | | | | sleep 240; grep -E "===|Elapsed|User time|exit" /tmp/bench.log | | | | | | 81 --- TOOL bash --- | | === bench5 | | exit=127 | | === bench5a | | exit=127 | | === bench5b | | exit=127 | | | | | | 82 --- ASSISTANT --- | | bash | | | | head -5 /tmp/bench.log; which time; ls /usr/bin/time 2 &1 | | | | | | 82 --- TOOL bash --- | | <stdout === bench5 | | /tmp/runbench.sh: line 4: /usr/bin/time: No such file or directory | | exit=127 | | === bench5a | | /tmp/runbench.sh: line 4: /usr/bin/time: No such file or directory | | ls: cannot access '/usr/bin/time': No such file or directory | | </stdout | | <stderr </stderr | | <returncode 2</returncode | | | | 83 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && cat /tmp/runbench.sh << 'EOF' | | /bin/bash | | cd /workspace/leanproject | | for f in bench5 bench5a bench5b; do | | echo "=== $f" /tmp/bench.log | | S=$ date +%s.%N | | timeout 900 lake env lean /tmp/$f.lean /tmp/bench.log 2 &1 | | echo "exit=$? elapsed=$ echo "$ date +%s.%N - $S" | bc " /tmp/bench.log | | done | | echo ALLDONE /tmp/bench.log | | EOF | | rm -f /tmp/bench.log && nohup /tmp/runbench.sh /dev/null 2 &1 & sleep 200; cat /tmp/bench.log | | | | | | 83 --- TOOL bash --- | | === bench5 | | | | | | 84 --- ASSISTANT --- | | I'm noticing that bench5 with stepTrue is taking over 3 minutes when it should be quick—just 69k iterations of a simple loop with basic operations. Earlier, a bare xrunStrip at 4320 iterations was essentially free, so something's off. The issue might be that mkrun is a higher-order function where step gets passed as a closure, so when stepTrue is applied inside expressions like step v .and ... , there's extra overhead from the variable application. But wait, I'm spotting what could be a serious problem... | | | | Looking at how benchWith calls mkrun with stepTrue: the loop guard checks if e3 v and continues until that's false, running about 2160 iterations per pair for a total of 69k—which should be fast based on bench4's evidence 4320 iterations took ~0.1s . But bench4 didn't have the framework overhead or the higher-order step parameter or the allB wrapper. The real question is whether mkrun's definition has step as a free variable captured inside the Nat.rec body—if mkrun takes step as a parameter and then Nat.rec references it, the kernel should unfold mkrun once per pair and substitute the concrete stepTrue, making it O 1 . The allB wrapper with 32 leaves is trivial. So why is this taking 200+ seconds? It's not the higher-order mechanics—something about the compilation of bench5's framework is pathological, maybe re-elaborating the Dev/Checker content which takes 8-13s alone plus something else entirely. | | | | Now I'm wondering about the actual evaluation: the benchWith expression uses let b := mkrun ...; b.or Bool.not b , which means b appears twice. Bool.or is lazy-ish it matches on the first argument and only evaluates the second if needed , but Bool.not b forces a second evaluation of the entire loop if the kernel doesn't cache the result of b's whnf. With pointer-sharing from the let binding, the node should be shared, but if the kernel doesn't cache big evaluations, then b gets re-evaluated—though that would only double the time, not cause a 200-second blowup. Maybe the real issue is the fuel value of 6000: with stepTrue the loop terminates early around 2160 iterations, but I need to reconsider whether something else is happening with the fuel handling. Checking bench5's theorems — only bT for stepTrue. The framework alone compiles in about 12-13 seconds, but bench5 is hitting 200+ seconds, which is way off. The culprit has to be either the higher-order mkrun, the let-sharing in benchWith, or the allB iteration over 32 pairs — one of these is causing a serious slowdown. My guess is the Bool.or operation is getting pathological somewhere. | | | | Actually, wait — I need to think about Bool.and more carefully. When we have step v .and cond ... , the second argument only gets evaluated if the first is true, so that's not the issue. But here's the real problem: Nat.rec on fuel might be fine, but at each recursion level we're rebuilding the motive type fun = Nat → Nat → Nat → Nat → Bool . The kernel's recursor reduction has to compute these motive types in weak-head normal form, and that could be where the exponential blowup is happening. | | | | I'm overthinking this without data though. Let me wait for bench5 to finish and compare the results between versions 5a and 5b. In the meantime, there's another suspect: the benchWith step p call with its beta-reduction of the let-binding for mkrun , where the initial value involves a complex arithmetic expression with p as a parameter. | | | | While waiting for the benchmark results, I should consider a fallback approach: going back to a plain balanced tree with leaf-local recomputation. The math works out to roughly 40-60 microseconds per leaf with optimizations, which would handle 100 million leaves in 1.5 to 2 hours—acceptable as a backup. But if bench5 reveals what's causing the stepTrue mystery, fixing that could push the linear loop down to 10-25 microseconds per operation, which would be much better. Let me see what the log shows. | | bash | | | | sleep 240; cat /tmp/bench.log; tail -1 /tmp/scan99.err | | | | | | 84 --- TOOL bash --- | | === bench5 | | /tmp/bench5.lean:82:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | /tmp/bench5.lean:82:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | /tmp/bench5.lean:88:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | /tmp/bench5.lean:88:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | /tmp/bench5.lean:94:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | /tmp/bench5.lean:94:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | exit=0 elapsed=336.761468105 | | === bench5a | | block 8/24 done marks=161429299425 zeros=0 | | | | | | 85 --- ASSISTANT --- | | Bench5 with stepTrue took 337 seconds, which means the loop over 69k iterations consumed about 320 seconds—roughly 4.6 milliseconds per iteration. The bare loop ran essentially free, so the performance issue is definitely in the benchWith/mkrun/allB structure, not in xstep itself. Interestingly, bench2 was faster at 101 seconds even though it used xcheck instead. | | | | The key difference is that higher-order mkrun adds about 3× overhead compared to direct xrun. When I compare xcheck 1.3ms per iteration against xrunStrip without the xstep wrapping, the addition of .and xstep v accounts for roughly 88 seconds of that 101-second total—but that's still puzzling because both paths force the same chained expression Nat.sub v' e3' . In xrunStrip, the guard Nat.ble e3 v forces it cheaply if chains stay shallow, while xcheck forces it through Nat.mod v Q1 first. The forcing order shouldn't cause a 50× slowdown, so I'm wondering if this is actually about term growth rather than just forcing order. | | | | The real issue might be how the kernel handles the DAG structure: each level builds expressions like Nat.sub v e3 Nat.add e3 e2 where the arguments grow as a DAG—linear in total nodes but exponential as a tree if the kernel walks it without caching. The e3 chain follows a Fibonacci-like growth pattern, so if whnf traverses the tree naively, it explodes exponentially. But since things do complete, there must be some whnf caching that keeps it manageable relative to the DAG size. | | | | With persistent caching across levels, each node gets evaluated exactly once, making the total work proportional to the number of nodes in the DAG—linear in fuel. That explains why xrunStrip is fast. But xcheck might behave differently depending on how it interacts with the kernel's whnf caches there seem to be multiple: whnf core cache and whnf cache , and operations like Nat.mod have their own fast-path reduction that might bypass or interact with caching differently. | | | | The real question is whether the Bool.and structure forces unnecessary re-evaluation—when xstep v gets cached and the conjunction short-circuits to evaluate the second component, that should be fine. But if the elaborator's pre-check and the kernel's type-checker maintain separate cache instances, that could cause double evaluation of the same expressions. So the key difference is how the cache works: when we construct fresh Nat.rec nodes at each level, there's no cache collision, but we're building new pointers each time. With benchWith and shared subexpressions like b.or Bool.not b , the WHNF of b gets computed once and cached by pointer, so subsequent uses hit the cache — but I'm wondering if Lean's expression cache actually uses pointer equality or structural hashing for the key. | | | | Rather than keep theorizing about the cache implementation, I should just measure directly: create a series of 5 intermediate test variants between the fast and slow benchmark shapes, keep them minimal and standalone without framework overhead, and systematically bisect to find where the performance cliff is. | | I found that the stepTrue loop is also slow at 4.6ms per iteration, meaning the problem is in the wrapper structure itself rather than the mask work. I'm now doing systematic bisection with standalone files to isolate the issue. | | bash | | | | cd /workspace/leanproject && cat /tmp/iso.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | namespace I | | | | def allB p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | p | | fun f ih a = ih a .and ih Nat.add a Nat.pow 2 f | | fuel | | | | def strip : Nat → Nat → Nat → Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Nat → Nat → Nat → Bool | | fun = false | | fun ih v e3 e2 e1 = | | cond Nat.ble e3 v | | ih Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true | | fuel | | | | def stripT : Nat → Nat → Nat → Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Nat → Nat → Nat → Bool | | fun = false | | fun ih v e3 e2 e1 = | | true .and | | cond Nat.ble e3 v | | ih Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true | | fuel | | | | -- V1: 32 calls via allB, no or-not all results are true since guard-stop | | def pair1 p : Nat : Bool := strip 6000 Nat.add Nat.mul 8 Nat.sub 908070605043 Nat.mul 977 p 1 8 24 24 | | set option maxHeartbeats 0 in | | theorem v1 : allB pair1 5 0 = true := by decide +kernel | | EOF | | cat /tmp/iso2.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | EOF | | sed -n '2,28p' /tmp/iso.lean /tmp/iso2.lean | | cat /tmp/iso2.lean << 'EOF' | | -- V2: single call of the .and true variant | | set option maxHeartbeats 0 in | | theorem v2 : stripT 6000 Nat.add Nat.mul 8 908070605043 1 8 24 24 = true := by decide +kernel | | EOF | | cat /tmp/runbench2.sh << 'EOF' | | /bin/bash | | cd /workspace/leanproject | | for f in iso iso2; do | | echo "=== $f" /tmp/bench2.log | | S=$ date +%s | | timeout 900 lake env lean /tmp/$f.lean 2 &1 | grep -cE "error" /tmp/bench2.log | | echo "exit=$? elapsed=$ $ date +%s - S " /tmp/bench2.log | | done | | echo ALLDONE /tmp/bench2.log | | EOF | | chmod +x /tmp/runbench2.sh && rm -f /tmp/bench2.log && nohup /tmp/runbench2.sh /dev/null 2 &1 & sleep 90; cat /tmp/bench2.log | | | | | | 85 --- TOOL bash --- | | === iso | | | | | | 86 --- ASSISTANT --- | | The slowdown in the benchmark comes from the allB wrapper or non-literal arguments like Nat.sub 908070605043 Nat.mul 977 p where p is an allB -chain expression, but when W was a literal in bench4, the single call executed instantly—so literal values bypass the performance bottleneck. | | | | Now I'm realizing the real issue: in the 32-call scenario, each Nat.rec iteration instantiates the body subtree with fresh nodes for all bound variables, which should be O |body| per level and fine for a single run, but somehow 32 identical runs balloon to 337 seconds—suggesting either the whnf cache gets invalidated between runs or there's exponential tree-walking happening without pointer-sharing across the recursion iterations. | | | | My next thought is that the cache might be size-limited and thrashing: a single 2160-iteration run creates around 20,000 cache entries which is manageable, but 32 runs generate 700,000+ entries, and if the cache uses structural hashing with deep argument chains as DAGs, collisions could force expensive structural equality checks that compound the slowdown. | | | | At this point I need to stop speculating and actually examine the Lean kernel behavior directly, but since that's not easily accessible, I should pivot to a pragmatic approach—maybe the balanced-tree architecture can help here. | | | | The tree-based approach gives predictable linear performance around 160 microseconds per leaf, which translates to about 6 microseconds per reduction operation. That's still suspiciously slow compared to bare arithmetic, likely due to the same hidden overhead from argument chains of depth ~12 where each leaf forces values up the tree, though caching should amortize this to O 1 . | | | | With the current setup—decide plus kernel overhead—9e7 leaves takes about 4 hours; switching to single-eval addDecl cuts that to 2 hours, and halving leaf operations brings it down to 1-1.5 hours. That's my fallback baseline. | | | | Before abandoning the linear loop approach, I want to try one more thing: encoding the state as a single number using a packing trick where I combine the three state values into one via bit shifts using a base like 2^48 , then decode and re-encode it each iteration with just a handful of bitwise operations instead of passing multiple arguments through the function call chain. | | | | But wait—the encoded state is still just an expression chain of arithmetic operations, not a materialized literal. Forcing it only helps if the branch guard fully evaluates it and caches the result, which gives me the same cache-dependent lookup I already have. That's no real improvement. | | | | The actual solution would need CPS or accumulator-style passing with literal values, but that's impossible in call-by-name without relying on the cache anyway. | | | | Actually, let me step back—maybe the bottleneck isn't the loop itself. The single-call benchmark was fast but 32 calls got slow. Could it be the allB and Nat.pow stride calculations instead? I'm wondering if the slowness comes from the defeq check itself — when the kernel evaluates decide allB pair1 5 0 = true = true , it's running through lazy delta reduction and whnf with different transparency levels, which might be causing repeated evaluation. I'm setting up a new experiment to isolate whether the .and wrapper in my stripT function is the bottleneck, since Bool.and's second argument is the recursive branch and the iota reduction might be creating unexpected overhead. Lean's and function matches on the first argument, returning false immediately if it's false , otherwise returning the second argument — so evaluation order is fine. I should wait for the iso2 result to complete before drawing any conclusions. | | bash | | | | sleep 420; cat /tmp/bench2.log; tail -1 /tmp/scan99.err | | | | | | 86 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 87 --- ASSISTANT --- | | bash | | | | cat /tmp/bench2.log; tail -1 /tmp/scan99.err | | | | | | 87 --- TOOL bash --- | | === iso | | 0 | | exit=1 elapsed=380 | | === iso2 | | 0 | | exit=1 elapsed=22 | | ALLDONE | | block 9/24 done marks=163446275871 zeros=0 | | | | | | 88 --- ASSISTANT --- | | Looking at the performance benchmarks, the first version with parameterized strip-calls is taking 380 seconds, which is way too slow, while the second version using a single stripT call with .and true is running around 8-17 seconds depending on the baseline measurement. The second approach is clearly more efficient, though I'm still trying to nail down the exact timing since the baseline measurements are a bit fuzzy. | | | | I think I've figured out what's causing the pathology: when the loop's initial value contains an unresolved parameter expression that depends on the allB chain, something goes quadratic or exponential. The first version initializes with a complex expression involving Nat operations and the parameter p, whereas the faster single-call version works with more literal expressions that the kernel can normalize once. The real issue seems to be how the kernel's type checker handles lazy delta unfolding through Nat.rec — it's using separate transparency layers and caching mechanisms that behave differently depending on whether the expression contains unresolved variables. | | | | The empirical pattern is clear: multiple loop runs where the parameters come from enclosing recursion-built expressions cause catastrophic slowdown, while literal-ish expressions don't. I should test whether literalizing the pair arguments before entering the loop would help, though in call-by-name evaluation that's tricky. Another angle worth checking quickly is whether each of the 32 runs is just hitting some fixed cost repeatedly. | | | | Looking at the actual difference between bench4 and the slower runs: bench4 had W as a raw literal from the source, while the slower versions have W as an expression depending on p. The key issue is that this W-expression appears in every guard check, and if the cache isn't working properly—maybe due to structural keying or hash collisions—then forcing the value chain costs O k per level instead of O 1 amortized. | | | | For k=2160, that compounds to roughly 2.3 million node-walks per run, times 32 runs gives 75 million walks total, which at 1-5 microseconds each matches the observed slowdown of 75-370 seconds. But bench4 with a literal W should still have the same chain structure and should be slow too, yet it ran in ~0.1 seconds—which doesn't add up unless the literal W gets constant-folded by the kernel, somehow avoiding the expensive chain traversals that the expression version can't escape. | | | | The real difference might be in how decide handles the equation: bench4 evaluates the chain through weak-head normal form cleanly, but iso's allB pair1 5 0 unfolds by forcing pair1 on each element, which triggers the strip-run evaluation per element instead of once. | | | | Maybe I should test an iso variant without allB — 32 separate theorems, each proving strip 6000 literal i 8 24 24 = true with pre-computed literal arguments generated in the source. If those are fast, the bottleneck is parameter-expression-dependence, and the fix is to generate code where all pair-level W values are source literals rather than computed in-kernel. That would be about 500KB of generated Lean code with explicit per-pair values instead of computing W = N − c6 − c8 at runtime. | | | | The tricky part is connecting those literals to the c6/c8 values through per-pair proofs — each pair needs to prove its literal equals N − c8·z − c6·y via reflexivity, which is cheap since c6/c8 are small. So the generated file would contain roughly 35,000 theorems, each one proving its pair's W value by decide , but the elaboration overhead alone could be 3–30 minutes, plus the kernel computation time for each theorem's decision procedure. | | | | Then combining all 35,000 lemmas into a master statement becomes its own problem: I'd need to build a tree of combiner lemmas using an allB-combining pattern, where each pair lemma feeds into a leafY2 check. For each z-value, that's about 511 combiner lemmas across 9 levels since y has 512 values , and with 160 z-values, that's 80,000+ additional lemmas — the generated file would be megabyte-scale and elaboration could take hours. | | | | Let me first verify the literal-args hypothesis though; there might be a simpler fix I'm missing. I'll test with a file containing 32 individual theorems, each checking strip 6000 on precomputed literal values generated via Python. | | I'm testing whether literal arguments are faster than parameterized ones by working through 32 individual literal-argument theorems. | | bash | | | | cd /workspace/leanproject && python3 -c " | | hdr = open '/tmp/iso2.lean' .read .split '-- V2' 0 | | out = hdr | | for p in range 32 : | | W = 908070605043 - 977 p | | A = 8 W+1 | | out.append f'set option maxHeartbeats 0 in\ntheorem w{p} : strip 6000 {A} 8 24 24 = true := by decide +kernel' | | open '/tmp/iso3.lean','w' .write '\n'.join out | | " && cat /tmp/rb3.sh << 'EOF' | | /bin/bash | | cd /workspace/leanproject | | S=$ date +%s | | timeout 900 lake env lean /tmp/iso3.lean 2 &1 | grep -cE "error" /tmp/bench3.log | | echo "exit=$? elapsed=$ $ date +%s - S " /tmp/bench3.log | | EOF | | chmod +x /tmp/rb3.sh && rm -f /tmp/bench3.log && nohup /tmp/rb3.sh /dev/null 2 &1 & sleep 120; cat /tmp/bench3.log | | | | | | 88 --- TOOL bash --- | | 0 | | exit=1 elapsed=45 | | | | | | 89 --- ASSISTANT --- | | I'm noticing that running 32 separate theorems with literal arguments takes around 45 seconds total, which breaks down to roughly 1 second per 2160 iterations—much slower than expected. Even with literal arguments and separate theorem invocations, each run is taking about a second, whereas a single bench4 run with 4320 iterations completes in under 0.3 seconds, suggesting there's significant overhead from the repeated theorem calls themselves. | | | | Looking at the bench4 measurements more carefully: the total file time is 6.7 seconds, identical to the baseline, which means the loop overhead is essentially zero. The guard condition appears correct—it stops at around 4320 iterations as expected. But when I compare bench4's fuel 12000 and weight 1.45e13 to iso3-literal's fuel 6000 and weight 9.08e11 , they have the same structure, yet bench4 runs free while iso3-literal costs about 1 second per invocation. I need to rerun the timing comparison more carefully, accounting for OS cache effects and whether the earlier bench4 measurement might have been skewed. | | | | The key difference seems to be that iso3 runs inside a namespace with additional definitions, and each of its 32 theorems goes through per-theorem elaboration overhead with the decide tactic. I'm wondering if the +kernel flag in the tactic actually bypasses elaboration-time evaluation and uses kernel reduction instead, which could explain the performance gap. The literal values match between runs, so that's not the issue. The real problem is timing noise from scan99 running in the background—it's creating contention that makes measurements unreliable. I should let scan99 finish its current phase while doing only lightweight work, then run clean benchmarks once it's done, since the marginal value of continuing scan99 beyond block 12 is questionable anyway. | | | | Alternatively, I could isolate the benchmarks by using taskset to pin them to a single core while letting scan99 use the others, or renice scan99 to the lowest priority so the benchmarks get dedicated CPU time—that should give me enough isolation to get accurate measurements without waiting. | | Timing noise from the scanner is confounding everything. Deprioritize it and get clean measurements: | | bash | | | | renice -n 19 -p $ pgrep -x scan99 /dev/null; cd /workspace/leanproject && cat /tmp/rb4.sh << 'EOF' | | /bin/bash | | cd /workspace/leanproject | | for f in "$@"; do | | echo "=== $f" /tmp/bench4.log | | S=$ date +%s | | timeout 900 nice -n -5 lake env lean /tmp/$f.lean 2 &1 | grep -cE "error" /tmp/bench4.log | | echo "elapsed=$ $ date +%s - S " /tmp/bench4.log | | done | | echo ALLDONE /tmp/bench4.log | | EOF | | chmod +x /tmp/rb4.sh | | rebuild the key comparison set: baseline / single / 32-literal-theorems / allB-32 | | python3 -c " | | hdr = '''import FormalConjectures.Util.ProblemImports | | namespace I | | def strip : Nat → Nat → Nat → Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Nat → Nat → Nat → Bool | | fun = false | | fun ih v e3 e2 e1 = | | cond Nat.ble e3 v | | ih Nat.sub v e3 Nat.add e3 e2 Nat.add e2 e1 Nat.add e1 8 | | true | | fuel | | ''' | | open '/tmp/ka.lean','w' .write hdr + 'theorem t : 2:Nat +2 = 4 := by decide +kernel\n' | | open '/tmp/kb.lean','w' .write hdr + 'set option maxHeartbeats 0 in\ntheorem t : strip 6000 7264584578345 8 24 24 = true := by decide +kernel\n' | | out= hdr | | for p in range 32 : | | A = 8 908070605043 - 977 p +1 | | out.append f'set option maxHeartbeats 0 in\ntheorem w{p} : strip 6000 {A} 8 24 24 = true := by decide +kernel' | | open '/tmp/kc.lean','w' .write '\n'.join out | | " | | rm -f /tmp/bench4.log && nohup /tmp/rb4.sh ka kb kc /dev/null 2 &1 & sleep 100; cat /tmp/bench4.log | | | | | | 89 --- TOOL bash --- | | === ka | | 0 | | elapsed=34 | | === kb | | 0 | | elapsed=28 | | === kc | | 0 | | elapsed=36 | | ALLDONE | | | | | | 90 --- ASSISTANT --- | | Looking at the baseline performance with the deprioritized scanner, the Mathlib import is taking around 34 seconds, which is much longer than expected—though that includes loading the oleans from a somewhat cold cache. The actual import overhead was measured at about 13.5 seconds in an idle state, so contention is still affecting I/O and CPU performance even with nice -5 helping. Now comparing relative performance across different configurations with varying workload parameters. The cache should persist across those 32 runs nested inside the kernel call, but empirically it's not working for the p-dependent chains the way it does for literal-rooted ones — possibly because isDefEq resets caches or applies different transparency rules per branch. The pragmatic solution is to generate separate theorems with literal arguments for each pair, since that configuration runs nearly free. | | | | At roughly 60ms per theorem including elaboration overhead, 35,000 pair-lemmas would take around an hour to generate, which is workable despite the file size ballooning to about 1.5MB. The challenge is combining all those lemmas back together efficiently — I could either build per-z y-tree combiners or explore larger structural units that still maintain the speed advantage of separate theorems with literals. | | | | The core issue is that injecting the y-loop directly into the kernel as in-kernel expressions reintroduces the pathology where the computation becomes p-dependent again. I need to run some targeted experiments to isolate exactly what triggers the slowdown — starting with a single theorem that has a deeply nested literal expression to see where the performance cliff appears. | | I've found that literal-argument runs are essentially free, so now I'm pinpointing the exact trigger for the issue. | | bash | | | | cd /workspace/leanproject && python3 -c " | | hdr = open '/tmp/ka.lean' .read .split 'theorem t' 0 | | allb = '''def allB p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | p | | fun f ih a = ih a .and ih Nat.add a Nat.pow 2 f | | fuel | | ''' | | A = 8 908070605043+1 | | E1: one theorem, v-init as compound literal expression | | open '/tmp/e1.lean','w' .write hdr + f'set option maxHeartbeats 0 in\ntheorem t : strip 6000 Nat.add Nat.mul 8 Nat.sub 908070605043 Nat.mul 977 17 1 8 24 24 = true := by decide +kernel\n' | | E2: conjunction of two literal runs in one theorem | | open '/tmp/e2.lean','w' .write hdr + f'set option maxHeartbeats 0 in\ntheorem t : strip 6000 {A} 8 24 24 .and strip 6000 {A-8 977} 8 24 24 = true := by decide +kernel\n' | | E3: allB over 32 pairs, W constant no p-dependence | | open '/tmp/e3.lean','w' .write hdr + allb + f'def pair p : Nat : Bool := strip 6000 {A} 8 24 24\nset option maxHeartbeats 0 in\ntheorem t : allB pair 5 0 = true := by decide +kernel\n' | | E4: allB over 32 pairs, W = A - 8 977 p | | open '/tmp/e4.lean','w' .write hdr + allb + f'def pair p : Nat : Bool := strip 6000 Nat.sub {A} Nat.mul 7816 p 8 24 24\nset option maxHeartbeats 0 in\ntheorem t : allB pair 5 0 = true := by decide +kernel\n' | | " | | rm -f /tmp/bench4.log && nohup /tmp/rb4.sh e1 e2 e3 e4 /dev/null 2 &1 & sleep 210; cat /tmp/bench4.log | | | | | | 90 --- TOOL bash --- | | === e1 | | 0 | | elapsed=10 | | === e2 | | 0 | | elapsed=31 | | === e3 | | 0 | | elapsed=21 | | === e4 | | | | | | 91 --- ASSISTANT --- | | bash | | | | sleep 120; cat /tmp/bench4.log; tail -1 /tmp/scan99.err | | | | | | 91 --- TOOL bash --- | | === e1 | | 0 | | elapsed=10 | | === e2 | | 0 | | elapsed=31 | | === e3 | | 0 | | elapsed=21 | | === e4 | | block 10/24 done marks=162865528290 zeros=0 | | | | | | 92 --- ASSISTANT --- | | bash | | | | sleep 240; cat /tmp/bench4.log | | | | | | 92 --- TOOL bash --- | | === e1 | | 0 | | elapsed=10 | | === e2 | | 0 | | elapsed=31 | | === e3 | | 0 | | elapsed=21 | | === e4 | | 0 | | elapsed=431 | | ALLDONE | | | | | | 93 --- ASSISTANT --- | | Looking at the performance benchmarks, e1 runs fast at 10 seconds as expected, e2 takes 31 seconds which is within normal variance, and e3 with the allB wrapper stays fast at 21 seconds. But e4 blows up to 431 seconds when the wrapper parameter depends on p, which is clearly the pathological case triggering the slowdown. | | | | The mechanism seems to be that when W depends on p, the substituted pair body creates a v-init expression containing the p-chain, and even though forcing it produces a literal, the subsequent loop guards still reference that v-init node in ways that break caching. The fix is straightforward: since Python generates the file, I can emit literal kernel loop arguments everywhere instead of expressions, structuring it so each z and y pair gets a pair-lemma with a concrete literal W value. | | | | But the naive approach of generating ~35,000 theorems with per-pair glue lemmas would add massive elaboration overhead—potentially 2-4 hours total. The better strategy is a hybrid: pack many literal runs into a single theorem using conjunction chains, similar to what e2 did with just 2 runs. I can index into a literal table of W values using bit operations on a packed bignum, extracting each W p with a simple shift and mask operation. | | | | The issue is that even with this optimization, the extracted value still depends on the p-chain structure, which forces the shift amount to be computed from the loop index—creating the same deep arithmetic dependency I'm seeing in e4. I need to figure out whether the real bottleneck is just "depends on p" generally, or specifically arithmetic chains that propagate too deeply through the loop. There might be a different issue at play here: when the kernel checks equality with decide , it uses structural comparison that progressively unfolds and reduces the left side step-by-step while comparing against the right side, rather than relying on the aggressive caching that pure weak-head-normal-form uses. | | | | In e3, the pair results are identical across all runs, so the kernel hits a cache after the first evaluation — the leaf applications all reduce to the same expression that's pointer-shared from the definition body, giving us one actual computation and thirty-one cache hits. That's why e3 is essentially free. | | | | But e4 shows the real problem: when there's actual per-parameter work, each run takes about 13 seconds, while separate theorems in kc only take 0.06–0.25 seconds each. So multiple distinct runs inside a single kernel isDefEq are roughly 50–100× slower than running them as separate theorems. Even e2, which has just two distinct runs in one theorem, shows each run taking around 10 seconds — still much slower than kc's 32 separate theorems completing in just 2 seconds total. | | | | The pattern is clear: a second run within the same kernel call becomes catastrophically slow, possibly due to cache poisoning after the first run fills the caches. The solution seems radical but necessary — one run per theorem, meaning 35,000 separate theorems for all the z,y -pairs. | | | | Though the tree benchmark earlier contradicts this: it ran linearly at 160 microseconds per leaf across 64 pairs and 2048 leaves all in one theorem, with no catastrophic per-run slowdown. The difference is that the tree has no strip-runs — just leaf-local computations where each leaf is nearly independent and does small whnf operations. So the catastrophe only appears when there's actual work happening across runs. | | | | The culprit seems to be the linear-chain loop specifically — when deep dependent chains run multiple times per kernel call. The chains interact badly with the cache: a single chain is fine, but a second chain becomes pathological. The Lean 4 kernel's whnf cache is an unbounded map with structural-hash-keyed lookups using structural equality. When comparing two deep-chain expressions that differ only deep inside, the equality check itself is O depth . On insert or lookup, bucket collisions force structural comparisons of keys, and with thousands of similar chain-nodes hashing nearby, each missed comparison becomes expensive. | | | | Now I'm looking at the empirical performance data across different computation patterns. Tree-structured computations with leaf-local work run linearly at around 160 microseconds per leaf, likely dominated by the leaf operations and node reductions. Linear strip loops run once per theorem with roughly 2160 iterations taking under a quarter second, which works out to maybe 30-70 microseconds per iteration based on the kernel call timings I'm seeing. | | | | The tree approach wins on engineering simplicity despite similar per-operation costs — it needs just one theorem per large chunk without the massive elaboration overhead that comes from needing 35,000 theorems plus glue code for the strip approach. Scaling the tree structure to 9×10^7 leaves at 160 microseconds each gives around 4 hours, but with optimizations to the leaf operations and single-pass evaluation I'm targeting closer to 1-1.5 hours. The tree computation also involves dependency chains through the leaf operations, which is exactly the structure I benchmarked earlier with the pair-dependent natural number subtraction. | | | | The key insight is that p-dependent leaves work fine in trees — the pathology only emerges with linear chain-state loops, which I'm avoiding entirely. So the final design uses balanced trees across all levels with leaf-local recomputation of the constants, where the pair-dependent values are computed once per pair at the tree level and then reused. This is the original leafX/xtreeOK design that already proved viable. | | | | Now I'm optimizing the leaf operation count by factoring out the shared computation and merging the guard check with the value computation to reduce redundant operations. Looking at the performance analysis now — the optimized leaf function with the special case for v ≤ 1 should reduce operations from 26-31 down to around 20, giving roughly a 1.3-1.5× speedup. The node computation stays efficient by using conditional logic instead of bitwise operations, and the masks plus bracket checks on survivors remain negligible. With the addDecl trick cutting operations by about 1.4×, I'm estimating around 57 microseconds per leaf, which scales to roughly 85 minutes total, and the double-check with addDecl should save another factor of 2. | | | | Now I'm working through the leaf count calculations for the test case at 1e12 — the x-leaves sum to somewhere between 1.2-1.3 times the average, and accounting for the distribution across pairs and triples, the total comes to around 9.4e7 leaves, which puts the runtime at approximately 90 minutes. | | | | Next I need to benchmark the addDecl optimization with the tree chunk to see if the single-pass approach beats the decide-plus-kernel version, then refine the leafX formula and verify the soundness proof using the ring identity for x x+1 x+2 x+3 . The remaining blocks hold most of the expected zeros, so if the scan comes back empty I'll need to either extend the search range further or explore other residue classes—like the 2 mod 9 class which has a slightly higher density, or the 8 mod 9 class—before deciding whether to push out to 3e13. | | I've confirmed that balanced trees with leaf-local computation are the way to go—they're reliably linear at around 160 microseconds per leaf—while linear chain-state loops are too slow for repeated kernel calls. I'll optimize the leaf implementation and test the addDecl single-evaluation trick, and the scan is currently at block 10 of 24 with no zeros found yet. | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | | | namespace D | | | | /- optimized leaf: 14 primitive ops typical -/ | | | | def leafX3 A8 x : Nat : Bool := | | -- A8 = 8 W+1 ; c4 x = x x+3 x x+3 +2 / 24 ; v = A8 - 8 c4 x | | let t := Nat.mul x Nat.add x 3 | | let c := Nat.div Nat.mul t Nat.add t 2 24 | | let v := Nat.sub A8 Nat.mul 8 c | | cond Nat.ble v 1 true sqTest v | | | | theorem c4 alt x : Nat : Nat.div Nat.mul Nat.mul x Nat.add x 3 Nat.add Nat.mul x Nat.add x 3 2 24 = c4 x := by | | rw c4 def, p4 def | | simp only mul eqn, add eqn, div eqn | | congr 1 | | ring | | | | theorem leafX3 sound {W x : Nat} h : leafX3 8 W+1 x = true : ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | have hc4 : Nat.div Nat.mul Nat.mul x Nat.add x 3 Nat.add Nat.mul x Nat.add x 3 2 24 = c4 x := c4 alt x | | rw leafX3 at h | | simp only hc4 at h | | -- now h : cond Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 true sqTest = true | | cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | | true = | | rw Nat.ble eq at hb | | simp only sub eqn, mul eqn at hb | | omega | | | false = | | rw hb, cond false at h | | have hlt : ¬ 8 W+1 - 8 c4 x ≤ 1 := by | | rw ← mul eqn, ← sub eqn, ← Nat.ble eq, hb ; simp | | have hv : Nat.sub 8 W+1 Nat.mul 8 c4 x = 2 w+3 2 w+3 := by | | simp only sub eqn, mul eqn | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | rw hv at h | | exact sqTest sound h 2 w+3 rfl | | | | /-- x-tree with optimized leaf; fx supplied, coverage checked via c4 2^fx ≥ W . -/ | | def xtreeOK3 W : Nat : Bool := | | let fx := Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 | | allB leafX3 Nat.add Nat.mul 8 W 1 fx 0 .and Nat.ble W c4 Nat.pow 2 fx | | | | theorem xtreeOK3 sound {W : Nat} h : xtreeOK3 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | intro w x heq | | simp only xtreeOK3 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq at h2 | | have ht := t2 ge one w | | have he : Nat.add Nat.mul 8 W 1 = 8 W+1 := by simp only add eqn, mul eqn | | rcases Nat.lt or ge x 2 ^ Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 with hx | hx | | · have hl := allB sound 0 h1 x Nat.zero le by omega | | rw he at hl | | exact leafX3 sound hl w heq | | · have hc : c4 Nat.pow 2 Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 ≤ c4 x := by | | apply c4 mono; rw pow eqn ; exact hx | | omega | | | | def leafY3 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK3 Nat.sub N b | | | | theorem leafY3 sound {N r8 y : Nat} h : leafY3 N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp | | simp only leafY3, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK3 sound h w x this | | | | def ytreeOK3 N fy r8 : Nat : Bool := | | allB leafY3 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | theorem ytreeOK3 sound {N fy r8 : Nat} h : ytreeOK3 N fy r8 = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | simp only ytreeOK3 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY3 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | def leafZ3 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true ytreeOK3 N fy r8 | | | | theorem leafZ3 sound {N fy z : Nat} h : leafZ3 N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ3, hb, cond false at h | | exact ytreeOK3 sound h w x y heq | | | | theorem master3 {N fy fz : Nat} | | h : allB leafZ3 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ3 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A6 | head -30 | | | | | | 93 --- TOOL bash --- | | Dev/Checker.lean:617:46: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | 8 W + 1 .sub Nat.mul 8 c4 x .ble 1 | | in the target expression | | ¬ Nat.mul 8 W + 1 .sub 8 c4 x .ble 1 = true | | | | W x w : ℕ | | heq : t2 w + c4 x = W | | | | | | 94 --- ASSISTANT --- | | I'm working through a naming conflict in the Lean proof where the expression 8 W+1 has different spellings depending on whether it's written as multiplication or using Nat.mul , and this is causing issues with the hypothesis after applying cases and simplification tactics. | | | | The fix is to construct the hypothesis hlt directly from hb using omega without trying to rewrite between different spellings — I'll phrase hlt in the exact same spelling as hb , then normalize both with simp only before letting omega handle the arithmetic reasoning. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | old = ''' have hlt : ¬ 8 W+1 - 8 c4 x ≤ 1 := by | | rw ← mul eqn, ← sub eqn, ← Nat.ble eq, hb ; simp''' | | new = ''' have hlt : ¬ Nat.sub 8 W+1 Nat.mul 8 c4 x ≤ 1 := by | | rw ← Nat.ble eq, hb ; simp | | simp only sub eqn, mul eqn at hlt''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A6 | head -20 | | | | | | 94 --- TOOL bash --- | | | | 95 --- ASSISTANT --- | | The optimized tree is proven and working. Now I need to benchmark the leafX3-tree against the old version and test the addDecl approach. For the final implementation, I'm using a Lean command that constructs equality expressions directly through the elaboration monad instead of relying on the decide tactic. | | | | The key insight is that the kernel only needs to perform a single evaluation when checking the declaration: it infers the type of the proof term which reduces to Eq Bool true true and verifies it matches the declared type which has the left-hand side as a complex expression that reduces to true . This single definitional equality check is what makes the approach efficient. | | | | I'm setting up benchmarks to compare both strategies: the decide+kernel approach with the chunk-based method. | | The optimized tree compiles successfully. Now I'll benchmark it against the addDecl single-eval trick. | | bash | | | | cd /workspace/leanproject && cat /tmp/b7.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | EOF | | sed '1,2d' Dev/Checker.lean /tmp/b7.lean | | cat /tmp/b7.lean << 'EOF' | | | | namespace D | | def benchP3 p : Nat : Bool := | | let b := xtreeOK3 Nat.sub 908070605043 Nat.mul 977 p | | b.or Bool.not b | | set option maxHeartbeats 0 in | | theorem bb3 : allB benchP3 5 0 = true := by decide +kernel | | end D | | EOF | | cp /tmp/b7.lean /tmp/b8.lean | | python3 - << 'PYEOF' | | src = open '/tmp/b8.lean' .read | | src = src.replace '''set option maxHeartbeats 0 in | | theorem bb3 : allB benchP3 5 0 = true := by decide +kernel''', | | '''open Lean in | | run cmd Lean.Elab.Command.liftCoreM <| Lean.addDecl <| .thmDecl { | | name := D.bb3 | | levelParams := | | type := Lean.mkApp3 Lean.mkConst Eq 1 Lean.mkConst Bool | | Lean.mkApp3 Lean.mkConst D.allB Lean.mkConst D.benchP3 Lean.mkNatLit 5 Lean.mkNatLit 0 | | Lean.mkConst Bool.true | | value := Lean.mkApp2 Lean.mkConst Eq.refl 1 Lean.mkConst Bool Lean.mkConst Bool.true | | }''' | | open '/tmp/b8.lean','w' .write src | | PYEOF | | rm -f /tmp/bench4.log && nohup /tmp/rb4.sh b7 b8 /dev/null 2 &1 & sleep 280; cat /tmp/bench4.log | | | | | | 95 --- TOOL bash --- | | === b7 | | 0 | | elapsed=83 | | === b8 | | 0 | | elapsed=102 | | ALLDONE | | | | | | 96 --- ASSISTANT --- | | Looking at the benchmark results for b7 and b8 — the leaf processing times are coming in much slower than expected, around 0.50ms per leaf compared to the 160μs baseline from earlier benchmarks. Even more puzzling, b8 with addDecl is taking longer than b7 with decide, which doesn't align with what the contention from the background scan should account for. | | | | Digging into what changed: the optimized leaf computation involves calculating t = x x+3 and similar operations, plus the new 4096-leaf trees have nearly half their leaves beyond the threshold where they're truncated to zero — those extra ~1900 cheap leaves should only add about 25% overhead, not triple the time. The p-dependent arithmetic in A8 is forced once per pair as expected. Something else must be causing this slowdown, possibly related to how the boolean logic in the benchmarking pattern is structured. | | | | Wait — I just realized the real culprit might be memory contention. I reniced the scan99 process to 19 and ran Lean with nice -n -5, but even as root, the kernel evaluation is memory-intensive with expression allocation happening constantly. Scan99 with 16 threads saturates RAM bandwidth regardless of CPU priority, so all these recent measurements are unreliable due to memory contention inflating times by 2-3×. I need to run clean measurements on an idle machine to get accurate numbers. | | | | Since scan99 is already halfway through block 11 of 24 with about 2 hours remaining , I'll pause it with SIGSTOP to run a quick A/B benchmark in about 4 minutes, then resume it afterward. | | I've identified that memory-bandwidth contention from the scanner was skewing the results, so I'm running a clean A/B test with the scanner fully stopped to get accurate numbers. | | bash | | | | pkill -STOP -x scan99; cd /workspace/leanproject && echo "=== b7 decide+kernel "; time timeout 400 lake env lean /tmp/b7.lean /dev/null 2 &1; echo "=== b8 addDecl "; time timeout 400 lake env lean /tmp/b8.lean /dev/null 2 &1; pkill -CONT -x scan99; echo resumed | | | | | | 96 --- TOOL bash --- | | | | real 0m27.712s | | user 0m27.434s | | sys 0m2.337s | | | | real 0m28.021s | | user 0m27.596s | | sys 0m2.543s | | | | === b7 decide+kernel | | === b8 addDecl | | resumed | | | | | | 97 --- ASSISTANT --- | | I'm working through the performance benchmarks for the Lean compiler, estimating that the framework baseline is around 15 seconds with the tree traversal contributing roughly 95 microseconds per leaf node, and noting that the addDecl operation appears to be equivalent to the decide and kernel extraction steps combined. | | bash | | | | pkill -STOP -x scan99; cd /workspace/leanproject && head -n -9 /tmp/b7.lean /tmp/b7base.lean && time timeout 400 lake env lean /tmp/b7base.lean /dev/null 2 &1; pkill -CONT -x scan99; echo done | | | | | | 97 --- TOOL bash --- | | | | real 0m13.319s | | user 0m13.277s | | sys 0m2.184s | | | | done | | | | | | 98 --- ASSISTANT --- | | I'm calculating the per-leaf cost from the b7 tree benchmark—subtracting the baseline overhead from the total time gives about 110 microseconds per leaf, accounting for a mix of cheap and expensive operations. Now I need to project this for the full dataset by summing across all leaf pairs. | | | | For n₀ around 10¹², I'm looking at roughly 94-130 million grid leaves, which would take 3-4 hours total—too slow. I'm exploring ways to reduce the per-leaf cost: the current 110μs comes from about 20 operations leaf logic plus node traversal , so roughly 5.5μs per operation, which seems high given the kernel overhead from dispatch, caching, and allocation. I'm considering micro-optimizations like replacing conditional branches with direct pattern matching or folding the v ≤ 1 check into the mask test, though there's a complication with division by zero when v=0 that forces me to keep the check separate. | | | | On the tree node side, I'm thinking about replacing the Nat.pow call with a literal half-width parameter to reduce the 6-8 operations per node, but that doesn't seem to save much. The bigger win might be tackling grid waste: currently rounding up to power-of-2 boundaries wastes about 45% of leaves on average. An alternative is building an allBUpTo variant that decomposes the limit in binary and covers exactly the needed leaves, which could save roughly 31% of the grid overhead. | | | | Even with that optimization though, the leaf count drops from 9.4e7 to 6.7e7, which only cuts the total time from about 2.4 hours down to 1.7 hours—not a huge win. The real question is whether I can parallelize across multiple Lean processes, but the final submission is a single file, and I don't know what timeout the verifier uses when it compiles the proof. If it's 1-2 hours, then a 3-4 hour file fails, so I need to aim for something under an hour to be safe. That means keeping n₀ small is critical—if the scan finds something like 2-4 trillion, the leaf count explodes to around 2.1e8, which is already pushing the limits. I can use the mod-9 structure to filter leaf candidates before testing them — precomputing which residues pass the modular constraint, then iterating only over those passing residues when building the x-tree. This cuts out about 59% of the leaves with just a couple extra operations per survivor, bringing the kernel work down significantly. | | | | Pushing this further with a combined mod-225 filter using the LCM of multiple modular periods gets even more aggressive: the pass rate drops to around 19%, so I'd only test about one-fifth of the original leaves, and even with the overhead of a two-level index decode, the net speedup climbs to roughly 4.3×. The key constraint is making sure the coverage argument holds — that every x not in the residue table is correctly ruled out by the mask-test. | | | | The trick is that the table itself depends on W mod 225, so I'd need 225 separate tables, one for each residue class. I can pack all of them into a single mega-literal blob indexed by W mod 225, extracting the right table with a shift and bitwise AND — about 3 operations per pair. The blob would be around 44KB, which is manageable as a literal in the source. | | | | Now I need to prove that this approach is sound: for every residue class r modulo 225 and every candidate x, if x isn't in the table for that class, then the quadratic form 8 Wr − c₄x + 1 definitely isn't a square modulo 225. This is a finite verification problem — 225 × 675 = 152,000 cases — that I can check once in the kernel with a decision procedure, taking maybe 15-30 seconds. Then at runtime, for each pair, I decode x and loop through the table entries for that residue class. | | | | The key optimization is using a tree structure where I compute x from an index i by splitting it into quotient and remainder parts relative to the table size, which varies by residue class. This avoids recomputing the same values and lets me batch operations. The filtering masks are partially redundant, so I'm reorganizing them around modulo 1089 to eliminate overlap. Overall this should give me a 2.5-3× speedup on the proof and coding phases combined. | | | | I'm settling on the current 110 microseconds per leaf design since it should handle up to 1.5 trillion leaves in 3-4 hours on a single thread, which is acceptable given the unknown verifier timeout risk. I'll implement further optimizations only if needed, though I should double-check whether Nat.pow is actually fast-pathed in the kernel for the exponents I'm using at nodes. | | | | Looking at the earlier measurements, the node machinery accounts for about 40 microseconds per leaf with trivial leaf work, leaving roughly 70 microseconds for actual leaf computation. Breaking down the node cost: binary trees require about 28 reductions across 4 nodes to handle 4 children, whereas 4-way branching could do the same work in roughly 10 reductions per node, which would significantly reduce the per-node overhead. | | | | Now I'm examining whether the leaf operations themselves have hidden costs. The modular arithmetic with Nat.mod on 43-bit values should be fast through GMP, but the bit-shifting operations on the large M1 value 7425 bits create new numbers that require heap allocation—potentially 460 bytes per operation, which could add a microsecond or two per shift. This suggests exploring smaller moduli like Q1 = 225 or Q2 = 297 to reduce allocation overhead while maintaining the necessary precision for the computation. The cumulative cost analysis shows this cascade approach uses roughly 5.8 operations compared to the current method's 5 operations, but with the major advantage that all the moduli are tiny—under 70 bytes each—so the actual bit shifts happen in just a few limbs and complete in microseconds. This makes the trade-off worthwhile. | | | | I'm verifying the mask-225 test works correctly: since 225 is odd and the quadratic residue image size is 44 out of 225 possibilities, that matches my earlier calculation. Now I'm thinking through the tree structure—an arity-4 tree targeting 50-60 microseconds per leaf would need around 94 million leaves to cover the search space, but the granularity issue with powers of 4 creates waste. I'm considering either a two-level approach with arity-4 down to size-16 blocks, or sticking with pure arity-4 and accepting the rounding overhead. | | | | The simpler option is keeping the grid as powers of 2 but structuring the tree as arity-4 by pairing binary levels, which requires even fuel values and gives similar waste ratios to before. Alternatively, I could implement a full 4-ary tree where the fuel determines the index range as powers of 4, and the waste factor works out to roughly 1.5× on average—comparable to the binary approach. Implementing hybrid approach... Now I'm working through the performance estimates: leaf operations should run around 30 microseconds with optimized shifts and modular arithmetic, plus another 10-15 microseconds per node, giving roughly 45-55 microseconds per leaf. That scales to about 80 minutes for the full dataset. If needed, I can apply residue-table skipping for another 2.5× speedup. Meanwhile, the scan is progressing through blocks 11-12 of 24, and once it finishes in a couple hours, I'll reassess whether to extend the current approach or widen the implementation class. | | I found that addDecl and decide +kernel both take about 110 microseconds per leaf with a 13.3 second baseline, and I'm implementing optimizations using 4-ary tree nodes and a cascade of small moduli to cut the cost roughly in half. | | bash | | | | cd /tmp && python3 << 'EOF' | | for q in 225, 539, 221, 437 : | | im = set j j % q for j in range q | | mask = 0 | | for u in im: mask |= 1 << u | | print f"-- q={q} |im|={len im } rate={len im /q:.4f}" | | print f"M{q} := {mask}" | | EOF | | | | | | 98 --- TOOL bash --- | | -- q=225 |im|=44 rate=0.1956 | | M225 := 134932278415263153289320518902861294585092876492072418360525652499 | | -- q=539 |im|=132 rate=0.2449 | | M539 := 30112542410578951545921030936162078674344692016917131568265818246077939783472096749940494893321507315275879452316783821055757733363335518344648930578722944289299 | | -- q=221 |im|=63 rate=0.2851 | | M221 := 1902691931378299041757545416576313148667104431336290058356702519827 | | -- q=437 |im|=120 rate=0.2746 | | M437 := 380006767722538127746873153178912511557101225749667469109215699828894109610685345234892465202245680870615963953941297072347087443 | | | | | | 99 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | | | namespace D | | | | /- cascade masks over small moduli cheap GMP shifts -/ | | | | def R1 : Nat := 225 | | def R2 : Nat := 539 | | def R3 : Nat := 221 | | def R4 : Nat := 437 | | def K1 : Nat := 134932278415263153289320518902861294585092876492072418360525652499 | | def K2 : Nat := 30112542410578951545921030936162078674344692016917131568265818246077939783472096749940494893321507315275879452316783821055757733363335518344648930578722944289299 | | def K3 : Nat := 1902691931378299041757545416576313148667104431336290058356702519827 | | def K4 : Nat := 380006767722538127746873153178912511557101225749667469109215699828894109610685345234892465202245680870615963953941297072347087443 | | | | set option maxHeartbeats 1000000 in | | theorem sqAllK1 : sqAll R1 K1 8 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllK2 : sqAll R2 K2 10 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllK3 : sqAll R3 K3 8 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllK4 : sqAll R4 K4 9 = true := by decide +kernel | | | | theorem maskK1 all : ∀ j : Nat, maskBit K1 j j % R1 = true := | | sqAll sound by norm num R1 by norm num R1 sqAllK1 | | theorem maskK2 all : ∀ j : Nat, maskBit K2 j j % R2 = true := | | sqAll sound by norm num R2 by norm num R2 sqAllK2 | | theorem maskK3 all : ∀ j : Nat, maskBit K3 j j % R3 = true := | | sqAll sound by norm num R3 by norm num R3 sqAllK3 | | theorem maskK4 all : ∀ j : Nat, maskBit K4 j j % R4 = true := | | sqAll sound by norm num R4 by norm num R4 sqAllK4 | | | | def sqTest2 v : Nat : Bool := | | cond Nat.beq Nat.land Nat.shiftRight K2 Nat.mod v R2 1 0 true | | cond Nat.beq Nat.land Nat.shiftRight K3 Nat.mod v R3 1 0 true | | cond Nat.beq Nat.land Nat.shiftRight K4 Nat.mod v R4 1 0 true | | bracketOK v | | | | theorem beq land zero {K q v : Nat} hall : ∀ j : Nat, maskBit K j j % q = true | | hb : Nat.beq Nat.land Nat.shiftRight K Nat.mod v q 1 0 = true : | | ∀ j : Nat, j j ≠ v := by | | intro j hj | | have m := hall j | | rw hj, maskBit at m | | rw Nat.beq eq at m hb | | omega | | | | theorem sqTest2 sound {v : Nat} h : sqTest2 v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | cases h2 : Nat.beq Nat.land Nat.shiftRight K2 Nat.mod v R2 1 0 with | | | true = exact beq land zero maskK2 all h2 j hj | | | false = | | cases h3 : Nat.beq Nat.land Nat.shiftRight K3 Nat.mod v R3 1 0 with | | | true = exact beq land zero maskK3 all h3 j hj | | | false = | | cases h4 : Nat.beq Nat.land Nat.shiftRight K4 Nat.mod v R4 1 0 with | | | true = exact beq land zero maskK4 all h4 j hj | | | false = | | rw sqTest2, h2, h3, h4, cond false, cond false, cond false at h | | exact bracketOK sound h j hj | | | | /- 4-ary tree -/ | | | | def allB4 p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | p | | fun f ih a = | | let s := Nat.pow 4 f | | ih a .and ih Nat.add a s .and ih Nat.add a Nat.mul 2 s .and ih Nat.add a Nat.mul 3 s | | fuel | | | | theorem allB4 sound {p : Nat → Bool} : ∀ f : Nat a : Nat , allB4 p f a = true → | | ∀ i, a ≤ i → i < a + 4^f → p i = true := by | | intro f | | induction f with | | | zero = | | intro a h i h1 h2 | | have : i = a := by omega | | simpa this using h | | | succ f ih = | | intro a h i h1 h2 | | have hs : allB4 p f+1 a = allB4 p f a .and allB4 p f a + 4^f .and | | allB4 p f a + 2 4^f .and allB4 p f a + 3 4^f := by | | show let s := Nat.pow 4 f; | | allB4 p f a .and allB4 p f Nat.add a s .and allB4 p f Nat.add a Nat.mul 2 s .and | | allB4 p f Nat.add a Nat.mul 3 s = | | simp only add eqn, mul eqn, pow eqn | | rw hs at h | | simp only Bool.and eq true at h | | obtain ⟨h0, hh1, hh2, hh3⟩ := h | | have hp : 4:Nat ^ f+1 = 4 4^f := by rw Nat.pow succ ; omega | | rcases Nat.lt or ge i a + 4^f with c1 | c1 | | · exact ih a h0 i h1 c1 | | rcases Nat.lt or ge i a + 2 4^f with c2 | c2 | | · exact ih a + 4^f hh1 i c1 by omega | | rcases Nat.lt or ge i a + 3 4^f with c3 | c3 | | · exact ih a + 2 4^f hh2 i c2 by omega | | · exact ih a + 3 4^f hh3 i c3 by omega | | | | /-- hybrid: covers a, a + 2^fx using 4-ary subtrees. -/ | | def allBH p : Nat → Bool fx a : Nat : Bool := | | cond Nat.beq Nat.mod fx 2 0 | | allB4 p Nat.div fx 2 a | | allB4 p Nat.div fx 2 a .and allB4 p Nat.div fx 2 Nat.add a Nat.pow 2 Nat.sub fx 1 | | | | theorem allBH sound {p : Nat → Bool} fx a : Nat h : allBH p fx a = true : | | ∀ i, a ≤ i → i < a + 2^fx → p i = true := by | | intro i h1 h2 | | rw allBH at h | | cases hb : Nat.beq Nat.mod fx 2 0 with | | | true = | | rw hb, cond true at h | | rw Nat.beq eq at hb | | have h4 : 4:Nat ^ fx/2 = 2^fx := by | | have : fx = 2 fx/2 := by omega | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | exact allB4 sound a h i h1 by omega | | | false = | | rw hb, cond false at h | | rw Bool.and eq true at h | | obtain ⟨ha, hb2⟩ := h | | rw Nat.beq eq at hb | | have hfx : fx = 2 fx/2 + 1 := by omega | | have h4 : 4:Nat ^ fx/2 = 2^ fx-1 := by | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | have he : Nat.add a Nat.pow 2 Nat.sub fx 1 = a + 2^ fx-1 := by | | simp only add eqn, pow eqn, sub eqn | | rw he at hb2 | | have hsplit : a + 2^fx = a + 2^ fx-1 + 2^ fx-1 := by | | have : 2:Nat ^fx = 2^ fx-1 + 2^ fx-1 := by | | rw show fx = fx-1 +1 from by omega, Nat.pow succ | | omega | | omega | | rcases Nat.lt or ge i a + 2^ fx-1 with c1 | c1 | | · exact allB4 sound a ha i h1 by omega | | · exact allB4 sound hb2 i c1 by omega | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A6 | head -30 | | | | | | 99 --- TOOL bash --- | | Dev/Checker.lean:757:2: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | a ≥ 0 | | where | | a := ↑v | | Dev/Checker.lean:826:33: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | e ≥ 0 | | c ≥ 0 | | b ≥ 0 | | b - c ≥ 0 | | b - c - d ≤ -1 | | -- | | Dev/Checker.lean:830:37: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | c ≥ 0 | | b ≥ 0 | | b - c ≥ 0 | | b - c - d ≤ -1 | | b - c - e ≥ 0 | | -- | | Dev/Checker.lean:835:8: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | Nat.beq ?m.226 ?m.227 = true | | in the target expression | | fx.mod 2 .beq 0 = false | | | | case false | | p : ℕ → Bool | | | | | | 100 --- ASSISTANT --- | | I'm looking at a proof error where omega is receiving inconsistent representations of the same value—one using the % operator and another using Nat.mod —which are syntactically different atoms even though they're semantically equivalent. I need to normalize the hypothesis by simplifying the modulo expression so both sides use the same representation. | | | | For the second issue around line 826, omega is struggling with arithmetic involving powers of 4 because it's seeing 2 4^f as a different linear term from 4^f + 4^f , even though they're equal. The real problem is that the hypothesis hp : 4^ f+1 = 4 4^f isn't in the context when omega needs it to unfold the power expression, so it can't establish the necessary equivalences between the constraint bounds. I'm checking whether the atom representation of 4^f is consistent across different parts of the proof — it appears in both c2 and in the hypothesis hh1 that came from the rewrite, so they should match. Let me try strengthening the omega call by explicitly simplifying the power notation first, or probe the actual failing goal interactively to see what's going wrong. In the c2-lt branch, c1 refers to the ge case and c2 to the lt case, so the names work out. The omega error constraints are puzzling though — they don't seem to match the expected pattern from c2, which should be i < a + 2 4^f. Let me try creating a standalone test file to inspect the goals directly and see what's actually being passed to omega. | | | | For the beq issue on line 835, I need to handle the false case properly. Since Nat.beq eq only matches equality to true, I should use Nat.ne of beq eq false to convert the false beq result into a proper inequality, then check whether that lemma name exists or if I need to simplify it differently. | | | | The real question is whether omega normalizes both Nat.mod and the % operator consistently. Earlier it rejected the expression because it saw Nat.land as an unrelated atom, not because of the mod spelling itself. I should try using simp only mod eqn to normalize the modular arithmetic before passing it to omega, since omega might recognize % more readily than the explicit Nat.mod form. | | | | Now I need to investigate what's happening with the allB4 sound issue. | | bash | | | | cd /workspace/leanproject && sed -n '810,835p' Dev/Checker.lean | | | | | | 100 --- TOOL bash --- | | | | /-- hybrid: covers a, a + 2^fx using 4-ary subtrees. -/ | | def allBH p : Nat → Bool fx a : Nat : Bool := | | cond Nat.beq Nat.mod fx 2 0 | | allB4 p Nat.div fx 2 a | | allB4 p Nat.div fx 2 a .and allB4 p Nat.div fx 2 Nat.add a Nat.pow 2 Nat.sub fx 1 | | | | theorem allBH sound {p : Nat → Bool} fx a : Nat h : allBH p fx a = true : | | ∀ i, a ≤ i → i < a + 2^fx → p i = true := by | | intro i h1 h2 | | rw allBH at h | | cases hb : Nat.beq Nat.mod fx 2 0 with | | | true = | | rw hb, cond true at h | | rw Nat.beq eq at hb | | have h4 : 4:Nat ^ fx/2 = 2^fx := by | | have : fx = 2 fx/2 := by omega | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | exact allB4 sound a h i h1 by omega | | | false = | | rw hb, cond false at h | | rw Bool.and eq true at h | | obtain ⟨ha, hb2⟩ := h | | rw Nat.beq eq at hb | | | | | | 101 --- ASSISTANT --- | | I'm working through the true case where I rewrite the hypothesis using Nat.beq eq to convert Nat.beq Nat.mod fx 2 0 = true into Nat.mod fx 2 = 0 , then use omega to derive fx = 2 fx/2 — though omega might not be recognizing the Nat.mod spelling, which could explain why most of the 826-830 errors are clustering here. | | | | The real issue is an atom mismatch: when I call allB4 sound , the goal expects i < a + 4^ Nat.div fx 2 but omega is seeing 4^ fx/2 spelled with division operator instead of Nat.div , so the atoms don't unify. I need to normalize the spelling by adding simp only mod eqn after the rewrite, and then carefully state the exponent equality h4 using Nat.div consistently so omega can match the atoms correctly. | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | | | old = ''' intro j hj | | have m := hall j | | rw hj, maskBit at m | | rw Nat.beq eq at m hb | | omega''' | | new = ''' intro j hj | | have m := hall j | | rw hj, maskBit at m | | simp only mod eqn at hb | | rw Nat.beq eq at m hb | | omega''' | | assert old in src; src = src.replace old, new | | | | fix allB4 sound: rename case vars and give omega pow succ facts | | old = ''' rw hs at h | | simp only Bool.and eq true at h | | obtain ⟨h0, hh1, hh2, hh3⟩ := h | | have hp : 4:Nat ^ f+1 = 4 4^f := by rw Nat.pow succ ; omega | | rcases Nat.lt or ge i a + 4^f with c1 | c1 | | · exact ih a h0 i h1 c1 | | rcases Nat.lt or ge i a + 2 4^f with c2 | c2 | | · exact ih a + 4^f hh1 i c1 by omega | | rcases Nat.lt or ge i a + 3 4^f with c3 | c3 | | · exact ih a + 2 4^f hh2 i c2 by omega | | · exact ih a + 3 4^f hh3 i c3 by omega ''' | | new = ''' rw hs at h | | simp only Bool.and eq true at h | | obtain ⟨h0, hh1, hh2, hh3⟩ := h | | have hp : 4:Nat ^ f+1 = 4 4^f := by rw Nat.pow succ ; omega | | rcases Nat.lt or ge i a + 4^f with c1 | c1 | | · exact ih a h0 i h1 c1 | | rcases Nat.lt or ge i a + 2 4^f with c2 | c2 | | · exact ih a + 4^f hh1 i c1 by omega | | rcases Nat.lt or ge i a + 3 4^f with c3 | c3 | | · exact ih a + 2 4^f hh2 i c2 by omega | | · exact ih a + 3 4^f hh3 i c3 by omega | | ''' | | keep same but the errors were probably about spelling in allBH; skip modifying allB4 sound body except keep. | | src = src.replace old, new | | | | old = ''' intro i h1 h2 | | rw allBH at h | | cases hb : Nat.beq Nat.mod fx 2 0 with | | | true = | | rw hb, cond true at h | | rw Nat.beq eq at hb | | have h4 : 4:Nat ^ fx/2 = 2^fx := by | | have : fx = 2 fx/2 := by omega | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | exact allB4 sound a h i h1 by omega | | | false = | | rw hb, cond false at h | | rw Bool.and eq true at h | | obtain ⟨ha, hb2⟩ := h | | rw Nat.beq eq at hb | | have hfx : fx = 2 fx/2 + 1 := by omega | | have h4 : 4:Nat ^ fx/2 = 2^ fx-1 := by | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | have he : Nat.add a Nat.pow 2 Nat.sub fx 1 = a + 2^ fx-1 := by | | simp only add eqn, pow eqn, sub eqn | | rw he at hb2 | | have hsplit : a + 2^fx = a + 2^ fx-1 + 2^ fx-1 := by | | have : 2:Nat ^fx = 2^ fx-1 + 2^ fx-1 := by | | rw show fx = fx-1 +1 from by omega, Nat.pow succ | | omega | | omega | | rcases Nat.lt or ge i a + 2^ fx-1 with c1 | c1 | | · exact allB4 sound a ha i h1 by omega | | · exact allB4 sound hb2 i c1 by omega ''' | | new = ''' intro i h1 h2 | | rw allBH at h | | cases hb : Nat.beq Nat.mod fx 2 0 with | | | true = | | rw hb, cond true at h | | rw Nat.beq eq at hb | | simp only mod eqn at hb | | have h4 : 4:Nat ^ Nat.div fx 2 = 2^fx := by | | simp only div eqn | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | exact allB4 sound a h i h1 by omega | | | false = | | rw hb, cond false at h | | rw Bool.and eq true at h | | obtain ⟨ha, hb2⟩ := h | | have hbn : fx % 2 ≠ 0 := by | | intro hcon | | rw show Nat.mod fx 2 = fx % 2 from rfl, hcon at hb | | simp at hb | | have h4 : 4:Nat ^ Nat.div fx 2 = 2^ fx-1 := by | | simp only div eqn | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | have he : Nat.add a Nat.pow 2 Nat.sub fx 1 = a + 2^ fx-1 := by | | simp only add eqn, pow eqn, sub eqn | | rw he at hb2 | | have hsplit : a + 2^fx = a + 2^ fx-1 + 2^ fx-1 := by | | have : 2:Nat ^fx = 2^ fx-1 + 2^ fx-1 := by | | rw show fx = fx-1 +1 from by omega, Nat.pow succ | | omega | | omega | | rcases Nat.lt or ge i a + 2^ fx-1 with c1 | c1 | | · exact allB4 sound a ha i h1 by omega | | · exact allB4 sound hb2 i c1 by omega ''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A8 | head -40 | | | | | | 101 --- TOOL bash --- | | Dev/Checker.lean:853:8: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | g ≥ 0 | | e ≥ 0 | | d ≥ 0 | | d - e ≤ 0 | | d - f ≤ -1 | | b ≥ 0 | | b - c + d - e ≤ -1 | | | | | | 102 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && sed -n '845,856p' Dev/Checker.lean | | | | | | 102 --- TOOL bash --- | | congr 1 | | omega | | have he : Nat.add a Nat.pow 2 Nat.sub fx 1 = a + 2^ fx-1 := by | | simp only add eqn, pow eqn, sub eqn | | rw he at hb2 | | have hsplit : a + 2^fx = a + 2^ fx-1 + 2^ fx-1 := by | | have : 2:Nat ^fx = 2^ fx-1 + 2^ fx-1 := by | | rw show fx = fx-1 +1 from by omega, Nat.pow succ | | omega | | omega | | rcases Nat.lt or ge i a + 2^ fx-1 with c1 | c1 | | · exact allB4 sound a ha i h1 by omega | | | | | | 103 --- ASSISTANT --- | | I'm working through a proof step where I need to show that fx = fx-1 +1 using the omega tactic, but this requires fx ≥ 1 , which should follow from the hypothesis that fx is odd—let me verify that constraint is available in the current context. | | | | The issue is that when I rewrite fx everywhere in the goal using this equality, it creates a mess: the goal becomes 2^ fx-1 +1 = 2^ fx-1 +1 -1 + ... , and after applying pow succ , the atoms don't match up cleanly for omega to solve. A cleaner approach might be to case-split on fx directly: if fx = 0 , that contradicts the oddness hypothesis, and if fx = succ k , then I can simplify the arithmetic and let omega handle the resulting equality. Completing the proof by extracting k from fx and simplifying the exponent arithmetic... | | bash | | | | cd /workspace/leanproject && python3 - << 'PYEOF' | | src = open 'Dev/Checker.lean' .read | | old = ''' have hsplit : a + 2^fx = a + 2^ fx-1 + 2^ fx-1 := by | | have : 2:Nat ^fx = 2^ fx-1 + 2^ fx-1 := by | | rw show fx = fx-1 +1 from by omega, Nat.pow succ | | omega | | omega''' | | new = ''' have hsplit : a + 2^fx = a + 2^ fx-1 + 2^ fx-1 := by | | have hpow : 2:Nat ^fx = 2^ fx-1 + 2^ fx-1 := by | | obtain ⟨k, rfl⟩ : ∃ k, fx = k+1 := ⟨fx-1, by omega⟩ | | simp only Nat.add sub cancel, Nat.pow succ | | omega | | omega''' | | assert old in src; src = src.replace old, new | | open 'Dev/Checker.lean','w' .write src | | PYEOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A8 | head -30 | | | | | | 103 --- TOOL bash --- | | | | 104 --- ASSISTANT --- | | Now I'm building the leafX4 function with cascade masks, which computes a value by taking the product of x and x+3 , then deriving a coefficient from that intermediate result, and subtracting it from A8. The function then checks if the result is small or if a specific bit test passes, using the same soundness argument as leafX3 with the beq land zero property for the K1 branch. After that I'll set up xtreeOK4 using allBH with leafX4 and adjusting A8 accordingly, then move on to leafY4 and ytree4 keeping the binary tree structure for y and z since the overhead is minimal at that range , define master4, and run the benchmarks. | | bash | | | | cd /workspace/leanproject && cat Dev/Checker.lean << 'EOF' | | | | namespace D | | | | /- final optimized leaf + trees v4 -/ | | | | def leafX4 A8 x : Nat : Bool := | | let t := Nat.mul x Nat.add x 3 | | let c := Nat.div Nat.mul t Nat.add t 2 24 | | let v := Nat.sub A8 Nat.mul 8 c | | cond Nat.ble v 1 true | | cond Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 true sqTest2 v | | | | theorem notSquare of tests {v : Nat} | | h : cond Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 true sqTest2 v = true : | | ∀ j : Nat, j j ≠ v := by | | intro j hj | | cases h1 : Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 with | | | true = exact beq land zero maskK1 all h1 j hj | | | false = | | rw h1, cond false at h | | exact sqTest2 sound h j hj | | | | theorem leafX4 sound {W x : Nat} h : leafX4 8 W+1 x = true : ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | have hc4 := c4 alt x | | rw leafX4 at h | | simp only hc4 at h | | cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | | true = | | rw Nat.ble eq at hb | | simp only sub eqn, mul eqn at hb | | omega | | | false = | | rw hb, cond false at h | | have hlt : ¬ Nat.sub 8 W+1 Nat.mul 8 c4 x ≤ 1 := by | | rw ← Nat.ble eq, hb ; simp | | simp only sub eqn, mul eqn at hlt | | have hv : Nat.sub 8 W+1 Nat.mul 8 c4 x = 2 w+3 2 w+3 := by | | simp only sub eqn, mul eqn | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | rw hv at h | | exact notSquare of tests h 2 w+3 rfl | | | | def xtreeOK4 W : Nat : Bool := | | let fx := Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 | | allBH leafX4 Nat.add Nat.mul 8 W 1 fx 0 .and Nat.ble W c4 Nat.pow 2 fx | | | | theorem xtreeOK4 sound {W : Nat} h : xtreeOK4 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | intro w x heq | | simp only xtreeOK4 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq at h2 | | have ht := t2 ge one w | | have he : Nat.add Nat.mul 8 W 1 = 8 W+1 := by simp only add eqn, mul eqn | | rcases Nat.lt or ge x 2 ^ Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 with hx | hx | | · have hl := allBH sound 0 h1 x Nat.zero le by omega | | rw he at hl | | exact leafX4 sound hl w heq | | · have hc : c4 Nat.pow 2 Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 ≤ c4 x := by | | apply c4 mono; rw pow eqn ; exact hx | | omega | | | | def leafY4 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK4 Nat.sub N b | | | | theorem leafY4 sound {N r8 y : Nat} h : leafY4 N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp | | simp only leafY4, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK4 sound h w x this | | | | def ytreeOK4 N fy r8 : Nat : Bool := | | allB leafY4 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | theorem ytreeOK4 sound {N fy r8 : Nat} h : ytreeOK4 N fy r8 = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | simp only ytreeOK4 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY4 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | def leafZ4 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true ytreeOK4 N fy r8 | | | | theorem leafZ4 sound {N fy z : Nat} h : leafZ4 N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ4, hb, cond false at h | | exact ytreeOK4 sound h w x y heq | | | | theorem master4 {N fy fz : Nat} | | h : allB leafZ4 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ4 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | EOF | | timeout 280 lake env lean Dev/Checker.lean 2 &1 | grep -E "error" -A6 | head -20 | | | | | | 104 --- TOOL bash --- | | | | 105 --- ASSISTANT --- | | The v4 pipeline is compiling successfully. Now I'm benchmarking v4 against v3 with the scanner paused, running a test that evaluates a large grid of 131,072 leaves across 32 pairs to measure performance differences. | | bash | | | | cd /workspace/leanproject && cat /tmp/b9.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | EOF | | sed '1,2d' Dev/Checker.lean /tmp/b9.lean | | cat /tmp/b9.lean << 'EOF' | | | | namespace D | | def benchP4 p : Nat : Bool := | | let b := xtreeOK4 Nat.sub 908070605043 Nat.mul 977 p | | b.or Bool.not b | | set option maxHeartbeats 0 in | | theorem bb4 : allB benchP4 5 0 = true := by decide +kernel | | end D | | EOF | | head -n -8 /tmp/b9.lean /tmp/b9base.lean | | pkill -STOP -x scan99; echo "== base"; time timeout 400 lake env lean /tmp/b9base.lean /dev/null 2 &1; echo "== v4 bench"; time timeout 400 lake env lean /tmp/b9.lean /dev/null 2 &1; pkill -CONT -x scan99; echo done | | | | | | 105 --- TOOL bash --- | | | | real 0m15.873s | | user 0m16.550s | | sys 0m2.148s | | | | real 0m29.809s | | user 0m29.570s | | sys 0m2.842s | | | | == base | | == v4 bench | | done | | | | | | 106 --- ASSISTANT --- | | The v4 optimization with 4-ary nodes and smaller masks didn't yield any improvement—still around 106μs per leaf compared to v3's 110μs. This suggests the bottleneck isn't in the node structure or mask operations themselves, but rather in the fundamental cost of each kernel reduction step, which seems to run about 5-7μs regardless of the approach. | | | | Looking at the numbers more carefully: if each leaf involves roughly 20 reductions at 5μs per reduction, that's consistent with earlier microbenchmarks showing 4-5μs per reduction as a hard floor. The kernel's weak head normal form evaluation with hashing and caching overhead per node is just inherently expensive in this setting. | | | | To break through this wall, I'd need to either drastically reduce the number of steps per leaf—maybe down to 8-9 steps to hit around 45μs—or try something radically different like batching verification across an entire y-slice using giant arithmetic operations on multi-million-bit numbers to collapse many kernel steps into just a few GMP operations. | | | | The certificate approach is tricky: I can't easily aggregate the per-slot modular checks across all x values, but maybe I could provide compressed certificates for each survivor value and have the kernel verify them cheaply without needing the full witness data in the file. | | | | The performance bottleneck is clear — checking 4e5 survivors with integer square root via Newton iteration takes a couple minutes, which is fine, but the real cost is the 9.4e7 grid leaves at the leaf level, each requiring roughly 15-20 computational steps c4 calculation, v computation, modular operations, conditionals, node sharing logic , which balloons to around 2 hours for the full 1e12 range. To optimize further I'd need to dig deeper into the computation structure. | | | | The key insight is using residue tables modulo 225 which factors as 9·25 to reduce the leaf count by about 5×, bringing runtime down to 25-30 minutes. For this I need to figure out the period of c4 modulo 225 — since c4 x = x x+1 x+2 x+3 /24 and the division by 24 includes a factor of 3, the period depends on how c4 behaves under modular arithmetic with respect to powers of 3 and 5. The period likely involves lcm calculations across the prime factorization, and I'm working through whether the period is around 5400 or if I need to track x modulo higher powers of 3 to capture the full behavior. The 3-adic valuation of p4 is always at least 1, so I need to work modulo 81 to determine p4/3 modulo 27, which then determines c4 modulo 9 after dividing by 8. This means the period is lcm 81, 25 = 2025, and I'm now setting up a table to check which W-residue classes modulo 225 actually pass the ξ condition. I'm working through the memory constraints for storing these lookup tables — with a fixed slot size of around 500 entries per class, the total blob would be about 155KB, which expands to roughly 375KB as a decimal literal in the file. The extraction process involves shifting and masking operations on this large number for each pair, which means copying about 75KB per pair across 35,000 pairs, totaling around 2.6GB of copies but still manageable at about 0.3 seconds. The actual extraction expression masks out the relevant 5500-bit slice from the shifted blob. | | | | For each leaf, I'm extracting the entry from the cached slice using modular arithmetic and bit operations — a few shifts, masks, and arithmetic to recover the encoded value — then using that to compute the actual index and decode the table entry, which gives me the survivors that pass the modular constraint. | | | | The key insight is that by filtering to only the passing entries upfront, I reduce the total work significantly: each leaf does about 16-18 operations but only on roughly 19.6% of the leaves, so the net cost drops to about a quarter of the naive approach. To make this sound, I need to verify the completeness lemma: for every residue class and every value not in the precomputed table, the modular constraint is guaranteed to fail — I can check this by enumerating all values and confirming the table captures exactly the survivors. | | | | Now I'm working through the precise formula for computing the modular value: given the base value a8r and the correction term 8·c4 ξ , I need to carefully handle the modular arithmetic to avoid underflow, so I'm defining an intermediate value that adds back a multiple of 225 to keep everything in the natural numbers before taking the final modulus. Now I'm working through the completeness check for the table: for each residue class and each possible ξ value, I compute u and verify that if it's a potential square K1-bit set , then ξ must appear in the corresponding table slice in the correct sorted order. This involves a kernel loop checking roughly 455K iterations with about 15 operations each, which should run in 30-45 seconds as a one-time verification. Then I need to establish soundness for the x-enumeration step... | | | | For coverage, I'm setting up a padded table structure where each residue class r has its own list length L r , and I pad shorter lists with sentinel values 2047 to align them to a power-of-two grid size based on the maximum list length. During decoding, if we hit a sentinel, we know there's no valid x in that slot, so we can safely skip it. The enumeration range for i is bounded by the ceiling of X̄+1 /2025 scaled by the grid size, ensuring we cover all x values up to the threshold. | | | | The distribution analysis shows that while the average list length is around 396 entries per class, the worst-case class might reach 500-600, creating padding waste of about 1.3–1.5×. Despite this overhead, the overall approach still yields roughly a 3× net gain in performance. For n₀ = 10¹², the enumerated-leaf phase processes about 2.6×10⁷ leaves at roughly 35 microseconds each including the 18-step decode , bringing the total time to around 15 minutes. | | | | Adding the per-pair overhead of about 1 second for the shift and setup operations across 3.5×10⁴ pairs gives a total runtime estimate of roughly 20 minutes. The decision hinges on the actual value of n₀: if it stays below 6×10¹¹, the current design should complete in 1–1.5 hours, which is acceptable; but if n₀ climbs to around 5×10¹², the table-based approach cuts the time from 6 hours down to 1.2 hours, making the optimization worthwhile. I'm waiting for the scan results from blocks 12 and beyond to come in before committing to this path, and I also need to verify how the mask cascade with R₁=225 affects the passing rate for the hard-class cases. | | | | For hard n₀ values, the v-values that satisfy the square residue condition modulo small primes are actually rarer, which means fewer candidates survive the filters—that's favorable because it reduces the number of solutions we have to process downstream. | | Version 4 shows no improvement at 106μs per leaf since the kernel's 5μs per reduction is the bottleneck, so further speedup would require enumerating only x in passing residue classes to reduce leaves by 4-5×, which depends on the counterexample size. I'll check the scan next. | | bash | | | | tail -2 /tmp/scan99.err; cat /tmp/scan99.out | | | | | | 106 --- TOOL bash --- | | block 11/24 done marks=163075255264 zeros=0 | | block 12/24 done marks=163150211256 zeros=0 | | | | | | 107 --- ASSISTANT --- | | I've completed about half the search space up to 5.1e12 with no zeros found, and I'm resuming at full speed now after benchmarking. While the scan continues, I'm working on the remaining code generation for chunking and combining, plus finalizing the Spec.lean template and its generation script, and I'm also preparing commands for extending the search beyond 1e13. | | | | For the range 1e13, 3e13 , I'm estimating around 47 blocks with marks growing slowly, which would take roughly 7-9 hours total. I'm planning to prioritize extending the 86 mod 99 class to 2e13 next since deeper searches give better odds per member, and I'm considering whether I can run two scans concurrently with reduced thread counts since the bottleneck is memory bandwidth rather than CPU. I'm also working through a probability estimate for finding zeros in the 5e12, 1e13 range based on empirical tail behavior from earlier windows, though the calculation is getting tangled—extrapolating from the low-count frequencies suggests maybe around 50 zeros expected in that range, but I need to double-check the math. ≈ 417? | | | | Still predicts around 20 expected zeros, but that's overcounting since I'm assuming all of P 4 comes from the λ min tail. The empirics are clear though—nothing in 5e12, so I'll keep scanning and if 1e13 turns up empty too, I'll expand the search range further. Let me bump the scan priority back up and get the code generation ready while this runs. | | Renice the scanner back to full speed, and build the final codegen script + template while waiting: | | bash | | | | renice -n 0 -p $ pgrep -x scan99 /dev/null 2 &1; tail -1 /tmp/scan99.err | | | | bash | | | | cd /workspace/leanproject && cat Dev/TestChunk.lean << 'EOF' | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | EOF | | sed '1,2d' Dev/Checker.lean Dev/TestChunk.lean | | cat Dev/TestChunk.lean << 'EOF' | | | | namespace D | | -- test the z-chunk + combiner pattern on a small fake N has representations, | | -- so use OR-true bench wrapper only for plumbing test of the combiner | | -- Actually test combining machinery with allB succ rewrites on trivial predicate: | | def trivZ z : Nat : Bool := Nat.ble z 1000000 | | | | theorem tc0 : allB trivZ 2 0 = true := by decide +kernel | | theorem tc1 : allB trivZ 2 4 = true := by decide +kernel | | theorem tc2 : allB trivZ 2 8 = true := by decide +kernel | | theorem tc3 : allB trivZ 2 12 = true := by decide +kernel | | | | theorem tc01 : allB trivZ 3 0 = true := by | | rw show 3:Nat = 2+1 from rfl, allB succ | | rw show 0:Nat + 2^2 = 4 by norm num | | rw tc0, tc1 | | rfl | | theorem tc23 : allB trivZ 3 8 = true := by | | rw show 3:Nat = 2+1 from rfl, allB succ | | rw show 8:Nat + 2^2 = 12 by norm num | | rw tc2, tc3 | | rfl | | theorem tcAll : allB trivZ 4 0 = true := by | | rw show 4:Nat = 3+1 from rfl, allB succ | | rw show 0:Nat + 2^3 = 8 by norm num | | rw tc01, tc23 | | rfl | | end D | | EOF | | timeout 280 lake env lean Dev/TestChunk.lean 2 &1 | grep -E "error" -A5 | head -20 | | | | | | 107 --- TOOL bash --- | | block 12/24 done marks=163150211256 zeros=0 | | | | | | 107 --- TOOL bash --- | | | | 108 --- USER --- | | | | You have been working on the task described above but have not yet completed it. Write a continuation summary that will allow you or another instance of yourself to resume work efficiently in a future context window where the conversation history will be replaced with this summary. Your summary should be structured, concise, and actionable. Include: | | | | - Task Overview | | The user's core request and success criteria | | Any clarifications or constraints they specified | | | | - Current State | | What has been completed so far | | Files created, modified, or analyzed with paths if relevant | | Key outputs or artifacts produced | | | | - Important Discoveries | | Technical constraints or requirements uncovered | | Decisions made and their rationale | | Errors encountered and how they were resolved | | What approaches were tried that didn't work and why | | | | - Next Steps | | Specific actions needed to complete the task | | Any blockers or open questions to resolve | | Priority order if multiple steps remain | | | | - Context to Preserve | | User preferences or style requirements | | Domain-specific details that aren't obvious | | Any promises made to the user | | | | | | Be concise but complete—err on the side of including information that would prevent duplicate work or repeated mistakes. Write in a way that enables immediate resumption of the task. | | | | | | 109 --- ASSISTANT --- | | CONTINUATION SUMMARY — 2-4-6-8 Conjecture Task OEIS A306477 | | | | Task Overview | | Settle the conjecture in /workspace/leanproject/Submission/Spec.lean : either prove theorem oeis 306477 conjecture 1 : ∀ n : ℕ, 0 < n → 0 < A306477 n or disprove it by deleting the theorem and adding theorem oeis 306477 conjecture 1.disproof : ¬ ∀ n : ℕ, 0 < n → 0 < A306477 n . This is Zhi-Wei Sun's open "2-4-6-8 conjecture" $2468 prize : every n 0 is T w +C x,4 +C y,6 +C z,8 where T = positive triangular number, other terms may be 0. | | | | Constraints : Final proof in single file /workspace/leanproject/Submission/Spec.lean ; keep import FormalConjectures.Util.ProblemImports only import ; don't alter conjecture statement/def of A306477; axioms only propext/Classical.choice/Quot.sound NO native decide ; decide +kernel verified to use zero axioms ✓. Toolchain: Lean 4.27.0, Mathlib v4.27.0, 16 cores, 123GB RAM. Budget used ~$40-50 of $200, ~5h of 72h started ~19:00, currently ~23:00 day 1 . Bash calls have 300s timeout — use nohup for long jobs. | | | | STRATEGY DECIDED: DISPROVE. Verified no counterexample ≤ 10^10 matches known verification . Statistical analysis shows counts are ≈Poisson λ loc where λ loc = 24.7·n^ 1/24 ·∏f p n mod p ; heavy lower tail exists in class n≡2 mod 3, 9 mod 11 worst local factors: mod 9→0.765 at r=5, mod 11→0.595 at r=9, mod 17→0.830, etc.; NO deeper cascade — factors stabilize at 9/121; mod 2^k all trivial . Counterexample plausibly findable at 10^12–10^13 in class n≡86 mod 99 . | | | | Current State | | | | Counterexample scan C program, RUNNING | | - /tmp/scan99.c → /tmp/scan99 : bucketed cache-friendly sieve marking n=s+T k coverage for class n≡86 mod 99. Running as nohup /tmp/scan99 1 10000000000000 /tmp/scan99.out 2 /tmp/scan99.err & . At block 12/24 n≤5.1e12 : ZERO counterexamples so far. ~1.6e11 marks/block, ~10-15 min/block at full priority was reniced to 19 during benchmarks — ensure renice -n 0 -p $ pgrep -x scan99 . Check: tail /tmp/scan99.err; cat /tmp/scan99.out prints "ZERO <n " lines if found . | | - Other tools: /tmp/sieve full coverage sieve, verified 1,10^10 all covered , /tmp/window samples exact counts for class 20 mod 33 in a window; dumps win .u16 files , /tmp/counts count histogram to 1e9 . | | - Empirical data: known cnt=1 values: 23343989, 39866594, 54847142, 394239767. Local factor tables in /tmp/factors.pkl python pickle, moduli 9,5,7,11,...,127 . λ̄ n ≈ 24.7·n^{1/24} globally; class-33 average matches predictions well var/mean 1.1–1.3 . | | | | Lean framework COMPILES CLEAN | | /workspace/leanproject/Dev/Checker.lean — complete generic verified checker, namespace D , all sound, compiles with zero errors ~16s . Contains: | | - allB binary balanced ∀-tree via explicit Nat.rec , allB sound , allB zero , allB succ rfl ; allB4 4-ary + allB4 sound ; allBH hybrid covering a, a+2^fx with 4-ary subtrees + allBH sound . | | - t2,p4,c4,p6,c6,p8,c8 Nat.mul/div spelling for kernel speed + def rfl bridges to standard notation + monotonicity c4 mono etc. via gcongr + t2 ge one , eight t2 : 8 t2 w + 1 = 2w+3 ² . | | - Notation bridges mul eqn/add eqn/sub eqn/div eqn/mod eqn/pow eqn all rfl — ESSENTIAL for omega/rw spelling mismatches were the recurring error; fix pattern: simp only sub eqn, mul eqn at h before omega . | | - Square filters: big masks Q1=7425/M1, Q2=10829/M2, Q3=12673/M3 files /tmp/mask .txt with sqAllM : by decide +kernel + mask all ; NEW small-moduli cascade R1=225/K1, R2=539/K2, R3=221/K3, R4=437/K4 + sqAllK + maskK all + beq land zero helper + sqTest2 + sqTest2 sound . | | - newton Newton isqrt, fuel 64, log2 seed — Nat.log2 works in kernel , bracketOK + bracketOK sound soundness needs NO Newton correctness, just bracket r²<v< r+1 ² . | | - v4 pipeline CURRENT BEST : leafX4 A8=8W+1 param; c4 via t=x x+3 , c=t t+2 /24; v=A8−8c; ble v 1 guard; K1 test; survivors→ sqTest2 + leafX4 sound ; xtreeOK4 per-pair fx = log2 24W /4+1, uses allBH, coverage check ble W c4 2^fx + sound; leafY4/ytreeOK4/leafZ4/master4 all sound. Also older v1 leafX/xtreeOK/master and v3 variants still in file harmless . | | - choose2 eq/choose4 eq/choose6 eq/choose8 eq bridging Nat.choose to t2/c4/c6/c8 via Nat.choose two right, Nat.choose eq descFactorial div factorial; proofs: congr 1; simp Nat.descFactorial ; ring . | | - Local copy of A306477 def exact match to Submission + A eq zero : ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N → A306477 N = 0 Finset.sum eq zero ×4 + if neg + choose bridges + test0 : A306477 0 = 0 validating the ENTIRE pipeline end-to-end. | | - Dev/TestChunk.lean : validated the chunk-combining pattern: per-chunk theorems allB p 2 a = true by decide +kernel , combined via rw show 3:Nat =2+1 from rfl, allB succ ; rw show 0:Nat +2^2=4 by norm num ; rw tc0, tc1 ; rfl — WORKS. | | | | Final file plan not yet written | | Generated Spec.lean = license-free header + original imports/A306477 def + framework namespace D + def N0 : ℕ := <counterexample + z-chunk theorems chunk i : allB leafZ4 N0 FY f a = true := by decide +kernel + combiner theorems → allB leafZ4 N0 FY FZ 0 = true → master4 → A eq zero → final: | | | | theorem oeis 306477 conjecture 1.disproof : ¬ ∀ n : ℕ, 0 < n → 0 < A306477 n := by | | intro h; have := h N0 by norm num ; rw A eq zero ... at this; exact lt irrefl 0 this | | | | Fuels: fz=8 256 z's, valid n0≤1.2e15 , fy=9 512 y's, valid n0<2.6e13 . Delete the original theorem oeis 306477 conjecture 1 ... := sorry . Also need small lemma A306477 bound argument is NOT needed master covers all ℕ; range restriction in A306477 handled since A eq zero uses sum eq zero directly . | | | | Important Discoveries kernel performance — CRITICAL | | - Kernel reduction ≈ 4-5μs/step; decide +kernel ≡ manual addDecl + Eq.refl true both single-eval; no advantage to addDecl — use by decide +kernel with set option maxHeartbeats 1000000 in or 0 . | | - Balanced trees with leaf-local recompute: reliably LINEAR, measured ~106-110μs per grid leaf v4, idle machine; baseline file compile 13-16s . 4-ary nodes + small masks gave NO improvement bottleneck is per-reduction cost, not GMP ops . | | - Linear chain-state loops Nat.rec passing accumulated arithmetic state are catastrophically slow when run 1 time per kernel call ~10s/run vs ~0.1s as single run or as separate theorems — xrun/xcheck approach ABANDONED code still in file, harmless . Root cause unclear whnf cache behavior ; do NOT reuse. | | - Elaborator whnf plain rfl stack-overflows/times out — always use decide +kernel . | | - Cost projection: leaves ≈ 1.4· triples with s≤n0 ≈ 9.4e7 at n0~1e12 → ~3h single-threaded kernel ; scales as n0^{13/24}. No parallelism within one lean file verified: no async elaboration . | | - Speedup reserve NOT implemented : enumerate only x in passing residues mod 225 period 2025 in x; per-W-residue tables as packed literal blob; needs ~455K-case completeness lemma by decide +kernel + digit-extraction lemmas → est. 3-4× fewer steps → ~20-40 min. Implement if n0 ~1.5e12. | | - Masks must be squares mod q applied to v=8m+1 soundness via Nat.mul mod , no parity issues; for odd q, all-squares = odd-squares image . | | - pkill gotcha: pkill -f scan matches own bash command — use pkill -x scan99 / pkill -STOP -x scan99 pause / -CONT resume . | | - Benchmarks are garbage while scan99 runs memory bandwidth — pause it for timing. | | | | Next Steps priority order | | 1. Monitor scan99 to completion ~1-2h left for blocks 13-24, i.e. n∈ 5.1e12, 1.02e13 . If ZERO found at n0: verify independently write a simple exhaustive C/Python checker for that single n0: enumerate all x,y,z with c4+c6+c8≤n0, check 8 n0−s +1 never an odd square ≥9; also verify n0≡86 mod 99, n0 0 . | | 2. If scan completes empty: launch extensions in background, in this order: a /tmp/scan99 10000000000000 20000000000000 class 86 mod 99 to 2e13, ~5-7h ; b sibling classes: recompile scan99.c with RES 20 and RES 53 mod 99; other mod-9 subclasses of 20 mod 33 for 1,1e13 . Also consider mod-9-agnostic class 20 mod 33 edit MOD/RES; MOD must be odd . Expected: tail is thinner than Poisson extrapolations suggested none ≤5e12 despite estimates of several — persistence needed; possibly go to 3-5e13 in 86 mod 99. | | 3. Once n0 found & verified: python-generate final Spec.lean: take Dev/Checker.lean content can prune v1/v2/v3 dead code: leafX/xtreeOK/leafY/ytreeOK/leafZ/master, xrun/xcheck/leafY2/ytreeOK2/leafZ2/master2, leafX3-family, sqTest/M1/M2/M3 big masks if only sqTest2 used — CHECK leafX4 uses K1+sqTest2 only , plug N0 literal, generate per-z chunk theorems z=0..~40 individually via allB leafZ4 N0 9 0 z -equivalents — actually chunk theorems should be leafZ4 N0 9 z = true for small z and allB leafZ4 N0 9 k a = true subtrees for larger z ranges where work is tiny , then combiner tree via the validated TestChunk rw-pattern up to allB leafZ4 N0 9 8 0 = true , then master4 + A eq zero + disproof. Simulate the entire checker in Python first exact same logic incl. fx formulas, guard semantics, newton fuel to guarantee every chunk returns true before running Lean. | | 4. Estimate kernel time from n0 size ~110μs × 1.4 × triples n0 ; if 2-3h, implement the mod-225 residue-table optimization design details in discoveries above . | | 5. Final checks: lake env lean Submission/Spec.lean clean; print axioms oeis 306477 conjecture 1.disproof must show only allowed axioms decide+kernel path gives none/propext ; remove Dev/ files and Submission/KBench.lean created during benchmarking — DELETE before submission ; ensure Spec.lean keeps original A306477 def and docstrings, original theorem deleted; then submit proof. | | | | Context to Preserve | | - Statement negation must be exactly ¬ ∀ n : ℕ, 0 < n → 0 < A306477 n per negateExpr mkNot of cleaned statement . | | - A306477 in Spec.lean sums over R=range n+1 ⁴ with if w+2 .choose 2 + x+3 .choose 4 + y+5 .choose 6 + z+7 .choose 8 = n then 1 else 0 ; A eq zero needs no range/bounds reasoning sum eq zero + master over all ℕ . | | - The verifier's compile timeout is unknown — minimize final file kernel time; prefer smallest n0 found. | | - Files: masks at /tmp/mask {7425,10829,12673}.txt; window dumps /tmp/win .u16; scan sources /tmp/scan99.c, /tmp/scan33.c, /tmp/sieve.c, /tmp/window.c, /tmp/counts.c; benchmark scripts /tmp/rb4.sh etc. | | - Known-good proof idioms in this Mathlib: Nat.ble eq/blt eq/beq eq are ... = true = prop equalities rw-able ; le or lt does NOT exist use Nat.lt or ge ; Nat.choose succ succ' for Pascal primed +1 version, then norm num for literal normalization ; cond true/cond false simp lemmas; omega treats Nat.mul x y vs x y as different atoms — always normalize spelling first. | | | | 110 --- USER --- | | Settle the conjecture in the Lean file /workspace/leanproject/Submission/Spec.lean : either replace its sorry with a complete proof, or disprove it by deleting the original theorem foo ... := sorry and adding a foo.disproof theorem proving its negation. Do not alter the statement of the conjecture. | | | | If disproving, write a foo.disproof theorem whose type is the negation prepending ¬ of the original conjecture, according to the specific negateExpr function: | | | | lean | | private def negateExpr e : Expr : MetaM Expr := do | | let e := ← instantiateMVars e .cleanupAnnotations | | return mkNot e | | | | | | Work inside the Lake project at /workspace/leanproject . Your final proof must be in the single file /workspace/leanproject/Submission/Spec.lean . You may use other files as you develop your proof. | | | | In your final submission file /workspace/leanproject/Submission/Spec.lean , do not add or remove import statements. The FormalConjectures.Util.ProblemImports import transitively pulls in all of Mathlib, and other utilities. | | | | Your submission may depend only on the following axioms: propext , Classical.choice , Quot.sound . Don't attempt to cheat with Lean loopholes, the verifier will reject such attempts. | | | | Your environment has the following available: | | A Lean 4 toolchain with Mathlib | | git , rg , and jq | | The sage computer algebra system | | python with the following libraries: sympy , mpmath , numpy , pantograph . | | Documentation for libraries is available at /opt/ | | | | Blindly searching for counterexamples using numerics is rarely a good approach. | | | | | | | | Advice about this task: | | | | The problem may be an open mathematical conjecture. This does not mean the task is impossible. Researchers in 2026 have demonstrated that LLMs like you can do new mathematics and settle major conjectures that had been open for decades. For example, the planar unit distance problem, first posed by Paul Erdős in 1946, was resolved by an LLM. | | Major Lean formalization efforts of known results have also been completed by LLMs. For example, in 2026 LLMs proved the strong prime number theorem in Lean. | | Ignore any feelings that the task is infeasible; you are miscalibrated. You have a track record of underestimating your capabilities. Proceed with courage and boundless ambition. | | For example, if Mathlib is missing a major theorem you need, prove it yourself from what is available. | | You have been given enough resources in tokens and time to complete proofs of many tens of thousands or hundreds of thousands of lines of Lean. Check remaining resources using the resources tool. The context window may be compacted numerous times. | | | | CONTEXT COMPACTION SUMMARY | | | | The following is a summary of work completed on this task so far: | | | | <summary | | CONTINUATION SUMMARY — 2-4-6-8 Conjecture Task OEIS A306477 | | | | Task Overview | | Settle the conjecture in /workspace/leanproject/Submission/Spec.lean : either prove theorem oeis 306477 conjecture 1 : ∀ n : ℕ, 0 < n → 0 < A306477 n or disprove it by deleting the theorem and adding theorem oeis 306477 conjecture 1.disproof : ¬ ∀ n : ℕ, 0 < n → 0 < A306477 n . This is Zhi-Wei Sun's open "2-4-6-8 conjecture" $2468 prize : every n 0 is T w +C x,4 +C y,6 +C z,8 where T = positive triangular number, other terms may be 0. | | | | Constraints : Final proof in single file /workspace/leanproject/Submission/Spec.lean ; keep import FormalConjectures.Util.ProblemImports only import ; don't alter conjecture statement/def of A306477; axioms only propext/Classical.choice/Quot.sound NO native decide ; decide +kernel verified to use zero axioms ✓. Toolchain: Lean 4.27.0, Mathlib v4.27.0, 16 cores, 123GB RAM. Budget used ~$40-50 of $200, ~5h of 72h started ~19:00, currently ~23:00 day 1 . Bash calls have 300s timeout — use nohup for long jobs. | | | | STRATEGY DECIDED: DISPROVE. Verified no counterexample ≤ 10^10 matches known verification . Statistical analysis shows counts are ≈Poisson λ loc where λ loc = 24.7·n^ 1/24 ·∏f p n mod p ; heavy lower tail exists in class n≡2 mod 3, 9 mod 11 worst local factors: mod 9→0.765 at r=5, mod 11→0.595 at r=9, mod 17→0.830, etc.; NO deeper cascade — factors stabilize at 9/121; mod 2^k all trivial . Counterexample plausibly findable at 10^12–10^13 in class n≡86 mod 99 . | | | | Current State | | | | Counterexample scan C program, RUNNING | | - /tmp/scan99.c → /tmp/scan99 : bucketed cache-friendly sieve marking n=s+T k coverage for class n≡86 mod 99. Running as nohup /tmp/scan99 1 10000000000000 /tmp/scan99.out 2 /tmp/scan99.err & . At block 12/24 n≤5.1e12 : ZERO counterexamples so far. ~1.6e11 marks/block, ~10-15 min/block at full priority was reniced to 19 during benchmarks — ensure renice -n 0 -p $ pgrep -x scan99 . Check: tail /tmp/scan99.err; cat /tmp/scan99.out prints "ZERO <n " lines if found . | | - Other tools: /tmp/sieve full coverage sieve, verified 1,10^10 all covered , /tmp/window samples exact counts for class 20 mod 33 in a window; dumps win .u16 files , /tmp/counts count histogram to 1e9 . | | - Empirical data: known cnt=1 values: 23343989, 39866594, 54847142, 394239767. Local factor tables in /tmp/factors.pkl python pickle, moduli 9,5,7,11,...,127 . λ̄ n ≈ 24.7·n^{1/24} globally; class-33 average matches predictions well var/mean 1.1–1.3 . | | | | Lean framework COMPILES CLEAN | | /workspace/leanproject/Dev/Checker.lean — complete generic verified checker, namespace D , all sound, compiles with zero errors ~16s . Contains: | | - allB binary balanced ∀-tree via explicit Nat.rec , allB sound , allB zero , allB succ rfl ; allB4 4-ary + allB4 sound ; allBH hybrid covering a, a+2^fx with 4-ary subtrees + allBH sound . | | - t2,p4,c4,p6,c6,p8,c8 Nat.mul/div spelling for kernel speed + def rfl bridges to standard notation + monotonicity c4 mono etc. via gcongr + t2 ge one , eight t2 : 8 t2 w + 1 = 2w+3 ² . | | - Notation bridges mul eqn/add eqn/sub eqn/div eqn/mod eqn/pow eqn all rfl — ESSENTIAL for omega/rw spelling mismatches were the recurring error; fix pattern: simp only sub eqn, mul eqn at h before omega . | | - Square filters: big masks Q1=7425/M1, Q2=10829/M2, Q3=12673/M3 files /tmp/mask .txt with sqAllM : by decide +kernel + mask all ; NEW small-moduli cascade R1=225/K1, R2=539/K2, R3=221/K3, R4=437/K4 + sqAllK + maskK all + beq land zero helper + sqTest2 + sqTest2 sound . | | - newton Newton isqrt, fuel 64, log2 seed — Nat.log2 works in kernel , bracketOK + bracketOK sound soundness needs NO Newton correctness, just bracket r²<v< r+1 ² . | | - v4 pipeline CURRENT BEST : leafX4 A8=8W+1 param; c4 via t=x x+3 , c=t t+2 /24; v=A8−8c; ble v 1 guard; K1 test; survivors→ sqTest2 + leafX4 sound ; xtreeOK4 per-pair fx = log2 24W /4+1, uses allBH, coverage check ble W c4 2^fx + sound; leafY4/ytreeOK4/leafZ4/master4 all sound. Also older v1 leafX/xtreeOK/master and v3 variants still in file harmless . | | - choose2 eq/choose4 eq/choose6 eq/choose8 eq bridging Nat.choose to t2/c4/c6/c8 via Nat.choose two right, Nat.choose eq descFactorial div factorial; proofs: congr 1; simp Nat.descFactorial ; ring . | | - Local copy of A306477 def exact match to Submission + A eq zero : ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N → A306477 N = 0 Finset.sum eq zero ×4 + if neg + choose bridges + test0 : A306477 0 = 0 validating the ENTIRE pipeline end-to-end. | | - Dev/TestChunk.lean : validated the chunk-combining pattern: per-chunk theorems allB p 2 a = true by decide +kernel , combined via rw show 3:Nat =2+1 from rfl, allB succ ; rw show 0:Nat +2^2=4 by norm num ; rw tc0, tc1 ; rfl — WORKS. | | | | Final file plan not yet written | | Generated Spec.lean = license-free header + original imports/A306477 def + framework namespace D + def N0 : ℕ := <counterexample + z-chunk theorems chunk i : allB leafZ4 N0 FY f a = true := by decide +kernel + combiner theorems → allB leafZ4 N0 FY FZ 0 = true → master4 → A eq zero → final: | | | | theorem oeis 306477 conjecture 1.disproof : ¬ ∀ n : ℕ, 0 < n → 0 < A306477 n := by | | intro h; have := h N0 by norm num ; rw A eq zero ... at this; exact lt irrefl 0 this | | | | Fuels: fz=8 256 z's, valid n0≤1.2e15 , fy=9 512 y's, valid n0<2.6e13 . Delete the original theorem oeis 306477 conjecture 1 ... := sorry . Also need small lemma A306477 bound argument is NOT needed master covers all ℕ; range restriction in A306477 handled since A eq zero uses sum eq zero directly . | | | | Important Discoveries kernel performance — CRITICAL | | - Kernel reduction ≈ 4-5μs/step; decide +kernel ≡ manual addDecl + Eq.refl true both single-eval; no advantage to addDecl — use by decide +kernel with set option maxHeartbeats 1000000 in or 0 . | | - Balanced trees with leaf-local recompute: reliably LINEAR, measured ~106-110μs per grid leaf v4, idle machine; baseline file compile 13-16s . 4-ary nodes + small masks gave NO improvement bottleneck is per-reduction cost, not GMP ops . | | - Linear chain-state loops Nat.rec passing accumulated arithmetic state are catastrophically slow when run 1 time per kernel call ~10s/run vs ~0.1s as single run or as separate theorems — xrun/xcheck approach ABANDONED code still in file, harmless . Root cause unclear whnf cache behavior ; do NOT reuse. | | - Elaborator whnf plain rfl stack-overflows/times out — always use decide +kernel . | | - Cost projection: leaves ≈ 1.4· triples with s≤n0 ≈ 9.4e7 at n0~1e12 → ~3h single-threaded kernel ; scales as n0^{13/24}. No parallelism within one lean file verified: no async elaboration . | | - Speedup reserve NOT implemented : enumerate only x in passing residues mod 225 period 2025 in x; per-W-residue tables as packed literal blob; needs ~455K-case completeness lemma by decide +kernel + digit-extraction lemmas → est. 3-4× fewer steps → ~20-40 min. Implement if n0 ~1.5e12. | | - Masks must be squares mod q applied to v=8m+1 soundness via Nat.mul mod , no parity issues; for odd q, all-squares = odd-squares image . | | - pkill gotcha: pkill -f scan matches own bash command — use pkill -x scan99 / pkill -STOP -x scan99 pause / -CONT resume . | | - Benchmarks are garbage while scan99 runs memory bandwidth — pause it for timing. | | | | Next Steps priority order | | 1. Monitor scan99 to completion ~1-2h left for blocks 13-24, i.e. n∈ 5.1e12, 1.02e13 . If ZERO found at n0: verify independently write a simple exhaustive C/Python checker for that single n0: enumerate all x,y,z with c4+c6+c8≤n0, check 8 n0−s +1 never an odd square ≥9; also verify n0≡86 mod 99, n0 0 . | | 2. If scan completes empty: launch extensions in background, in this order: a /tmp/scan99 10000000000000 20000000000000 class 86 mod 99 to 2e13, ~5-7h ; b sibling classes: recompile scan99.c with RES 20 and RES 53 mod 99; other mod-9 subclasses of 20 mod 33 for 1,1e13 . Also consider mod-9-agnostic class 20 mod 33 edit MOD/RES; MOD must be odd . Expected: tail is thinner than Poisson extrapolations suggested none ≤5e12 despite estimates of several — persistence needed; possibly go to 3-5e13 in 86 mod 99. | | 3. Once n0 found & verified: python-generate final Spec.lean: take Dev/Checker.lean content can prune v1/v2/v3 dead code: leafX/xtreeOK/leafY/ytreeOK/leafZ/master, xrun/xcheck/leafY2/ytreeOK2/leafZ2/master2, leafX3-family, sqTest/M1/M2/M3 big masks if only sqTest2 used — CHECK leafX4 uses K1+sqTest2 only , plug N0 literal, generate per-z chunk theorems z=0..~40 individually via allB leafZ4 N0 9 0 z -equivalents — actually chunk theorems should be leafZ4 N0 9 z = true for small z and allB leafZ4 N0 9 k a = true subtrees for larger z ranges where work is tiny , then combiner tree via the validated TestChunk rw-pattern up to allB leafZ4 N0 9 8 0 = true , then master4 + A eq zero + disproof. Simulate the entire checker in Python first exact same logic incl. fx formulas, guard semantics, newton fuel to guarantee every chunk returns true before running Lean. | | 4. Estimate kernel time from n0 size ~110μs × 1.4 × triples n0 ; if 2-3h, implement the mod-225 residue-table optimization design details in discoveries above . | | 5. Final checks: lake env lean Submission/Spec.lean clean; print axioms oeis 306477 conjecture 1.disproof must show only allowed axioms decide+kernel path gives none/propext ; remove Dev/ files and Submission/KBench.lean created during benchmarking — DELETE before submission ; ensure Spec.lean keeps original A306477 def and docstrings, original theorem deleted; then submit proof. | | | | Context to Preserve | | - Statement negation must be exactly ¬ ∀ n : ℕ, 0 < n → 0 < A306477 n per negateExpr mkNot of cleaned statement . | | - A306477 in Spec.lean sums over R=range n+1 ⁴ with if w+2 .choose 2 + x+3 .choose 4 + y+5 .choose 6 + z+7 .choose 8 = n then 1 else 0 ; A eq zero needs no range/bounds reasoning sum eq zero + master over all ℕ . | | - The verifier's compile timeout is unknown — minimize final file kernel time; prefer smallest n0 found. | | - Files: masks at /tmp/mask {7425,10829,12673}.txt; window dumps /tmp/win .u16; scan sources /tmp/scan99.c, /tmp/scan33.c, /tmp/sieve.c, /tmp/window.c, /tmp/counts.c; benchmark scripts /tmp/rb4.sh etc. | | - Known-good proof idioms in this Mathlib: Nat.ble eq/blt eq/beq eq are ... = true = prop equalities rw-able ; le or lt does NOT exist use Nat.lt or ge ; Nat.choose succ succ' for Pascal primed +1 version, then norm num for literal normalization ; cond true/cond false simp lemmas; omega treats Nat.mul x y vs x y as different atoms — always normalize spelling first. | | </summary | | | | Please continue working on this task from where you left off. | | | | 111 --- ASSISTANT --- | | I'm checking the current progress on scan99 and reviewing what resources are available. | | bash | | | | tail -5 /tmp/scan99.err; echo ---; cat /tmp/scan99.out; echo ---; pgrep -x scan99 && ps -o pid,ni,etime,pcpu -p $ pgrep -x scan99 | | | | resources {} | | | | 111 --- TOOL bash --- | | block 9/24 done marks=163446275871 zeros=0 | | block 10/24 done marks=162865528290 zeros=0 | | block 11/24 done marks=163075255264 zeros=0 | | block 12/24 done marks=163150211256 zeros=0 | | block 13/24 done marks=163405443524 zeros=0 | | --- | | --- | | 1538 | | PID NI ELAPSED %CPU | | 1538 19 01:54:11 397 | | | | | | 111 --- TOOL resources --- | | Reaching any of the limits ends the task. | | - Token cost: $45.12 used, $154.88 remaining limit $200.00 | | - Tokens: 18,099,083 used no limit set | | - Time: 2h 43m 46s used, 69h 16m 14s remaining limit 72h | | | | 112 --- ASSISTANT --- | | The scan is progressing through block 13 of 24 with no zeros found yet in the range up to about 5.5 trillion. The process is running at nice level 19, so I should renice it to 0 to speed things up — it's already using 397% CPU across what looks like four threads. While that's running, I need to work on the mod-225 optimization design and get the Python simulator ready for the checker, plus finish the Spec.lean generator script and set up the sibling scans. | | | | Let me renice the process and check the scan99.c source to confirm the threading configuration. | | The scan is at block 13/24 with zero counterexamples found so far. Let me renice it to full priority and check its configuration. | | bash | | | | renice -n 0 -p 1538; ps -o pid,ni,pcpu,nlwp -p 1538; head -60 /tmp/scan99.c | | | | | | 112 --- TOOL bash --- | | renice: failed to set priority for 1538 process ID : Permission denied | | | | PID NI %CPU NLWP | | 1538 19 397 16 | | // Scan n ≡ 86 mod 99 for A306477 n =0, n in NLO,NHI . Bucketed marking. | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <string.h | | include <math.h | | include <omp.h | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | typedef uint32 t u32; | | static inline u64 isqrt64 u64 x { u64 r= u64 sqrtl long double x ; while r 0&&r r x r--; while r+1 r+1 <=x r++; return r;} | | define MOD 99ULL | | define RES 86ULL | | define LOGB 22 // members per bucket = 2^22 bitset 512KB | | define VCAP 65536 // marks per vector | | | | int main int argc,char argv { | | u64 NLO=strtoull argv 1 ,0,10 , NHI=strtoull argv 2 ,0,10 ; | | u64 NMAX=NHI-1; | | long n4=0,n6=0,n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; n4++;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; n6++;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; n8++;} | | u64 c4=malloc 8 n4 , c6=malloc 8 n6 , c8=malloc 8 n8 ; | | n4=n6=n8=0; | | for u64 a=3;;a++ { u128 v= u128 a a-1 a-2 a-3 /24; if v NMAX break; c4 n4++ = u64 v;} | | for u64 b=5;;b++ { u128 v= u128 b b-1 b-2 b-3 b-4 b-5 /720; if v NMAX break; c6 n6++ = u64 v;} | | for u64 c=7;;c++ { u128 v= u128 c c-1 c-2 c-3 c-4 c-5 c-6 c-7 /40320; if v NMAX break; c8 n8++ = u64 v;} | | long cap=0; | | pragma omp parallel for reduction +:cap | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { if c4 i +c6 j +c8 k NMAX break; cap++;}} | | u64 S3=malloc 8 cap ; long nS3=0; | | for long i=0;i<n4;i++ for long j=0;j<n6;j++ { if c4 i +c6 j NMAX break; for long k=0;k<n8;k++ { u64 s=c4 i +c6 j +c8 k ; if s NMAX break; S3 nS3++ =s;}} | | fprintf stderr,"|S3|=%ld %.2f GB \n",nS3,nS3 8.0/1e9 ; | | int ks 99 12 , nks 99 ; memset nks,0,sizeof nks ; | | for int k=0;k<99;k++ { int t= int u64 k k+1 /2 %99 ; ks t nks t ++ =k; } | | u64 JLO= NLO<=RES ?0: NLO-RES+MOD-1 /MOD; | | u64 JHI= NHI<=RES ?0: NHI-RES+MOD-1 /MOD; | | const u64 BB=1ULL<<32; | | u64 nblocks= JHI-JLO+BB-1 /BB; | | u64 bits=malloc BB/8 ; | | int NT=omp get max threads ; | | long totzeros=0; unsigned long long totmarks=0; | | for u64 bl=0;bl<nblocks;bl++ { | | u64 j0=JLO+bl BB, j1=j0+BB; if j1 JHI j1=JHI; | | u64 nb=j1-j0; | | u64 nwords= nb+63 /64; | | pragma omp parallel for | | for u64 w=0;w<nwords;w++ bits w =0; | | u64 nlo=RES+MOD j0, nhi=RES+MOD j1-1 ; | | u64 nbuck= nb+ 1ULL<<LOGB -1 LOGB; | | unsigned long long blockmarks=0; | | pragma omp parallel reduction +:blockmarks | | { | | u32 vec=malloc size t nbuck VCAP 4 ; | | int vn=calloc nbuck,sizeof int ; | | pragma omp for schedule dynamic,8192 nowait | | for long i=0;i<nS3;i++ { | | u64 s=S3 i ; | | if s nhi continue; | | | | | | 113 --- ASSISTANT --- | | The renice command failed because I can't lower the nice value as a non-root user, and we'd already set it to 19. The process is using 16 threads with 397% CPU utilization, which suggests it's not fully saturating the available cores—likely hitting a memory-bound bottleneck rather than being CPU-limited by the nice value itself. | | | | I'm considering whether to kill and restart the process at nice 0 from the current checkpoint around block 14, which corresponds to n ≈ 5.5e12 , since we've already scanned 13 blocks without finding counterexamples. The restart cost is minimal since the sieve setup is fast, but first I should check the instantaneous CPU usage with top or pidstat to see if we're actually hitting a performance wall right now or if the 397% is just a lifetime average. | | | | While the scan continues, I want to start preparing the Python simulator for the Lean checker and the Spec.lean generator script, plus get the sibling class scan sources ready. | | Renice failed since I'm not root, so I'll check the current CPU usage to decide whether to restart the scan at normal priority. | | bash | | | | top -b -n 2 -d 3 -p 1538 | tail -4; uptime | | | | | | 113 --- TOOL bash --- | | MiB Swap: 1024.0 total, 1024.0 free, 0.0 used. 112704.8 avail Mem | | | | PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND | | 1538 root 39 19 7692820 6.3g 1992 R 412.6 5.1 7,35 scan99 | | 21:50:25 up 5 days, 5:33, 0 user, load average: 88.08, 84.84, 73.27 | | | | | | 114 --- ASSISTANT --- | | The load average of 88 is concerning, especially with scan99 only using 412% CPU across 4 cores on a 16-core machine — something else must be driving the contention. I should check the overall process list and verify whether I'm running as root, since that could affect what I'm seeing. | | The load average is high at 88 but scan99 is only using 4 cores, so something else is consuming resources. I'll investigate what's hogging the machine. | | bash | | | | whoami; top -b -n 1 | head -25; nproc | | | | | | 114 --- TOOL bash --- | | root | | top - 21:50:37 up 5 days, 5:34, 0 user, load average: 88.25, 85.03, 73.52 | | Tasks: 30 total, 2 running, 6 sleeping, 0 stopped, 22 zombie | | %Cpu s : 0.0 us, 0.0 sy, 0.0 ni,100.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st | | MiB Mem : 126758.4 total, 65972.0 free, 14338.3 used, 47660.7 buff/cache | | MiB Swap: 1024.0 total, 1024.0 free, 0.0 used. 112420.1 avail Mem | | | | PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND | | 1538 root 39 19 7692820 6.3g 1992 R 413.3 5.1 7,36 scan99 | | 1 root 20 0 2524 1520 1412 S 0.0 0.0 0:00.27 tail | | 171 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 bash | | 292 root 20 0 0 0 0 Z 0.0 0.0 4:47.53 python3 | | 615 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 bash | | 854 root 20 0 0 0 0 Z 0.0 0.0 0:00.55 lake | | 900 root 20 0 0 0 0 Z 0.0 0.0 4:03.34 lean | | 918 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 pkill | | 978 root 20 0 0 0 0 Z 0.0 0.0 1:59.62 lean | | 997 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 bash | | 999 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 bash | | 1000 root 20 0 0 0 0 Z 0.0 0.0 0:00.35 lake | | 1046 root 20 0 0 0 0 Z 0.0 0.0 2:07.27 lean | | 1071 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 pkill | | 1456 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 pkill | | 1536 root 20 0 3932 1596 1324 S 0.0 0.0 0:00.00 bash | | 4437 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 timeout | | 4438 root 20 0 0 0 0 Z 0.0 0.0 0:00.00 grep | | 16 | | | | | | 115 --- ASSISTANT --- | | We're running as root, so the renice failure with "Permission denied" is strange—likely a container limitation where CAP SYS NICE is missing. The load average of 88 contradicts the idle CPU reading, which suggests the container might be CPU-throttled despite having 16 logical processors available. I should check the cgroup cpu.max setting to see if there's a hard limit restricting actual CPU usage. | | bash | | | | cat /sys/fs/cgroup/cpu.max 2 /dev/null; cat /sys/fs/cgroup/cpu.stat 2 /dev/null | head; cat /proc/self/status | grep -i cpus allowed list | | | | | | 115 --- TOOL bash --- | | max 100000 | | usage usec 41758676693 | | user usec 41544864426 | | system usec 213812266 | | nice usec 301939408 | | core sched.force idle usec 0 | | nr periods 0 | | nr throttled 0 | | throttled usec 0 | | nr bursts 0 | | burst usec 0 | | Cpus allowed list: 0-15 | | | | | | 116 --- ASSISTANT --- | | The cpu.max setting shows no quota, but scan99 is only hitting around 413% CPU usage. With 16 threads and a load average of 88, it seems like threads are mostly waiting rather than actively running—the marking phase appears to be memory-bandwidth constrained, though that should still register as CPU time. I'm wondering if the host might be shared or if there's something else limiting the actual CPU utilization. | | | | Looking at the top snapshot, it shows 100% idle while scan99 reports 413%, which is strange. The load average of 88 likely includes other containers or processes on the host, and since we're running at nice 19, other processes at nice 0 are outcompeting us for CPU cycles. That explains why renice would help, but we don't have CAP SYS NICE. The workaround is to kill and restart scan99 at the default nice level from a block boundary so it starts at nice 0 instead. | | | | For the block numbering, "block 13/24 done" suggests either 1-indexed output or that blocks 0 through 13 are complete. The earlier summary mentioned "block 12/24", so I need to check the actual code to see how the block counter is printed. | | The container doesn't have CAP SYS NICE and the host is busy, so the scan is only getting about 4 effective cores at nice-19. I'll kill and restart it at default nice from the current position, but first let me check the progress-print code to find the exact resume point. | | bash | | | | sed -n 60,120p /tmp/scan99.c | | | | | | 116 --- TOOL bash --- | | if s nhi continue; | | int r= int RES+MOD 2000ULL-s%MOD %MOD ; | | u64 tlo= nlo s ?nlo-s:1; | | u64 thi=nhi-s; | | for int q=0;q<nks r ;q++ { | | int km=ks r q ; | | u64 kmin= isqrt64 8 tlo+1 -1 /2; if kmin<1 kmin=1; | | while kmin kmin+1 /2<tlo kmin++; | | u64 k=kmin+ km+ int MOD- int kmin%MOD %MOD ; | | u64 t=k k+1 /2; | | while t<=thi { | | u64 j= s+t-RES /MOD - j0; | | u64 bkt=j LOGB; | | int pn=&vn bkt ; | | vec bkt VCAP + pn ++ = u32 j; | | blockmarks++; | | if pn==VCAP { | | u32 V=&vec bkt VCAP ; | | for int q2=0;q2<VCAP;q2++ { u64 jj=V q2 ; atomic fetch or &bits jj 6 ,1ULL<< jj&63 , ATOMIC RELAXED ; } | | pn=0; | | } | | t+=MOD k+MOD MOD+1 /2; k+=MOD; | | } | | } | | } | | // flush residuals | | for u64 b=0;b<nbuck;b++ { | | u32 V=&vec b VCAP ; | | for int q2=0;q2<vn b ;q2++ { u64 jj=V q2 ; atomic fetch or &bits jj 6 ,1ULL<< jj&63 , ATOMIC RELAXED ; } | | } | | free vec ; free vn ; | | } | | totmarks+=blockmarks; | | long z=0; | | pragma omp parallel for reduction +:z | | for u64 j=0;j<nb;j++ { | | if bits j 6 j&63 &1 { | | u64 n=RES+MOD j0+j ; | | if n =NLO { z++; | | pragma omp critical | | { printf "ZERO %llu\n", unsigned long long n ; fflush stdout ; } | | } | | } | | } | | totzeros+=z; | | fprintf stderr,"block %llu/%llu done marks=%llu zeros=%ld\n", unsigned long long bl+1, unsigned long long nblocks,blockmarks,z ; | | } | | fprintf stderr,"DONE %llu,%llu zeros=%ld totmarks=%llu\n", unsigned long long NLO, unsigned long long NHI,totzeros,totmarks ; | | return 0; | | } | | | | | | 117 --- ASSISTANT --- | | So blocks are 1-indexed in the output, meaning "block 13/24 done" indicates I've completed blocks 0 through 12, covering the range j ∈ JLO, JLO+13·2^32 . With NLO=1, that puts JLO at 0, so I've scanned n values from 86 up to approximately 5.53 trillion without finding any counterexamples. Now I'm restarting the process with NLO set to 86 to continue the search from there. | | | | For the restart, I'm deciding whether to extend NHI to 2×10^13 instead of stopping at 10^13, since the remaining blocks 14-24 only reach about 1.02×10^13 anyway. The S3 array size scales with NHI according to roughly N^ 13/24 , so doubling N would increase memory by a factor of about 1.45—manageable. With full 16 cores, each block should take around 5 minutes, and extending to 2×10^13 would require roughly 35 blocks total instead of the original 24, but this avoids needing another restart later. | | | | I'm also weighing whether to run this at nice priority 0 instead of 19 to compete better for CPU on the host, since the load is already at 88 and our container is getting throttled. Adding sibling class scans would further divide throughput, so I'll focus on this single scan at higher priority. | | | | My plan is to kill the current scan99 process and restart it with nice-0 priority covering the remaining range, then use that time to build out the Python simulator and spec generator. First, let me check the first line of scan99.err to verify the S3 size. | | I've scanned through block 12 up to approximately 5.5 trillion with no counterexamples found. Now I'll restart from that boundary and extend the search to 20 trillion. | | bash | | | | head -1 /tmp/scan99.err; kill 1538; sleep 1; python3 -c "print 86+99 13 2 32 " | | | | | | 117 --- TOOL bash --- | | |S3|=238659134 1.91 GB | | 5527622910038 | | | | | | 118 --- ASSISTANT --- | | bash | | | | cd /tmp && nohup ./scan99 5527622910038 20000000000000 /tmp/scan99b.out 2 /tmp/scan99b.err & sleep 20; ps -o pid,ni,pcpu -p $ pgrep -x scan99 ; head -2 /tmp/scan99b.err | | | | | | 118 --- TOOL bash --- | | PID NI %CPU | | 6918 0 395 | | |S3|=348144743 2.79 GB | | | | | | 119 --- ASSISTANT --- | | The CPU is still bottlenecked around 395% even after restarting at nice 0, likely because the S3 build phase has inherent serial sections and the host load of 88 might be capping us anyway. While that settles, I'm shifting focus to building a Python simulator for the Lean checker and working on the Spec.lean generator—I need to trace through Dev/Checker.lean's v4 pipeline to understand the exact semantics I'm working with. | | I've restarted at nice 0 and now I'm building a Python simulator of the Lean v4 checker pipeline by reviewing the code in Dev/Checker.lean. | | bash | | | | grep -n "leafX4\|xtreeOK4\|leafY4\|ytreeOK4\|leafZ4\|master4\|A eq zero\|sqTest2\|def K1\|def K2\|def K3\|def K4\|def R1\|allBH\|def newton\|bracketOK" /workspace/leanproject/Dev/Checker.lean | head -60 | | | | | | 119 --- TOOL bash --- | | 113:def newtonAux v : Nat : Nat → Nat → Nat := | | 121:def newton v : Nat : Nat := | | 125:def bracketOK v : Nat : Bool := | | 129:theorem bracketOK sound {v : Nat} h : bracketOK v = true : ∀ j : Nat, j j ≠ v := by | | 131: rw bracketOK, Bool.and eq true at h | | 183: bracketOK v | | 198: exact bracketOK sound h j hj | | 360:theorem A eq zero {N : Nat} hN : ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N : | | 373: A eq zero master N:=0 fy:=1 fz:=1 by decide +kernel by decide +kernel | | 717:def R1 : Nat := 225 | | 721:def K1 : Nat := 134932278415263153289320518902861294585092876492072418360525652499 | | 722:def K2 : Nat := 30112542410578951545921030936162078674344692016917131568265818246077939783472096749940494893321507315275879452316783821055757733363335518344648930578722944289299 | | 723:def K3 : Nat := 1902691931378299041757545416576313148667104431336290058356702519827 | | 724:def K4 : Nat := 380006767722538127746873153178912511557101225749667469109215699828894109610685345234892465202245680870615963953941297072347087443 | | 744:def sqTest2 v : Nat : Bool := | | 748: bracketOK v | | 760:theorem sqTest2 sound {v : Nat} h : sqTest2 v = true : ∀ j : Nat, j j ≠ v := by | | 771: rw sqTest2, h2, h3, h4, cond false, cond false, cond false at h | | 772: exact bracketOK sound h j hj | | 814:def allBH p : Nat → Bool fx a : Nat : Bool := | | 819:theorem allBH sound {p : Nat → Bool} fx a : Nat h : allBH p fx a = true : | | 822: rw allBH at h | | 866:def leafX4 A8 x : Nat : Bool := | | 871: cond Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 true sqTest2 v | | 874: h : cond Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 true sqTest2 v = true : | | 881: exact sqTest2 sound h j hj | | 883:theorem leafX4 sound {W x : Nat} h : leafX4 8 W+1 x = true : ∀ w, t2 w + c4 x ≠ W := by | | 887: rw leafX4 at h | | 907:def xtreeOK4 W : Nat : Bool := | | 909: allBH leafX4 Nat.add Nat.mul 8 W 1 fx 0 .and Nat.ble W c4 Nat.pow 2 fx | | 911:theorem xtreeOK4 sound {W : Nat} h : xtreeOK4 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | 913: simp only xtreeOK4 at h | | 920: · have hl := allBH sound 0 h1 x Nat.zero le by omega | | 922: exact leafX4 sound hl w heq | | 927:def leafY4 N r8 y : Nat : Bool := | | 929: cond Nat.ble N b true xtreeOK4 Nat.sub N b | | 931:theorem leafY4 sound {N r8 y : Nat} h : leafY4 N r8 y = true : | | 941: simp only leafY4, hb, cond false at h | | 944: exact xtreeOK4 sound h w x this | | 946:def ytreeOK4 N fy r8 : Nat : Bool := | | 947: allB leafY4 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | 949:theorem ytreeOK4 sound {N fy r8 : Nat} h : ytreeOK4 N fy r8 = true : | | 952: simp only ytreeOK4 at h | | 958: · exact leafY4 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | 963:def leafZ4 N fy z : Nat : Bool := | | 965: cond Nat.ble N r8 true ytreeOK4 N fy r8 | | 967:theorem leafZ4 sound {N fy z : Nat} h : leafZ4 N fy z = true : | | 974: simp only leafZ4, hb, cond false at h | | 975: exact ytreeOK4 sound h w x y heq | | 977:theorem master4 {N fy fz : Nat} | | 978: h : allB leafZ4 N fy fz 0 = true | | 984: · exact leafZ4 sound allB sound 0 h z Nat.zero le by omega w x y heq | | | | | | 120 --- ASSISTANT --- | | bash | | | | sed -n 100,200p /workspace/leanproject/Dev/Checker.lean; echo ======; sed -n 700,1000p /workspace/leanproject/Dev/Checker.lean | | | | | | 120 --- TOOL bash --- | | | | The output of your call to bash was too long to be displayed. | | Here is a truncated version: | | <START TOOL OUTPUT | | def sqAll q mask : Nat fq : Nat : Bool := | | allB fun u = maskBit mask Nat.mod Nat.mul u u q fq 0 | | | | theorem sqAll sound {q mask fq : Nat} hq : 0 < q hle : q ≤ 2^fq | | h : sqAll q mask fq = true : ∀ j : Nat, maskBit mask j j % q = true := by | | intro j | | have hj : j % q < q := Nat.mod lt hq | | have h2 := allB sound fq 0 h j % q Nat.zero le by omega | | have e : j % q j % q % q = j j % q := by rw ← Nat.mul mod | | have h3 : maskBit mask j % q j % q % q = true := h2 | | rwa e at h3 | | | | /-- Newton iteration for isqrt; result is just a candidate, soundness never relies on it. -/ | | def newtonAux v : Nat : Nat → Nat → Nat := | | fun fuel = Nat.rec motive := fun = Nat → Nat | | fun g = g | | fun ih g = | | let g2 := Nat.div Nat.add g Nat.div v g 2 | | cond Nat.blt g2 g ih g2 g | | fuel | | | | def newton v : Nat : Nat := | | newtonAux v 64 Nat.pow 2 Nat.add Nat.div Nat.log2 v 2 1 | | | | /-- check r r < v < r+1 r+1 for r = newton v ; implies v is not a square. -/ | | def bracketOK v : Nat : Bool := | | let r := newton v | | Nat.blt Nat.mul r r v .and Nat.blt v Nat.mul Nat.add r 1 Nat.add r 1 | | | | theorem bracketOK sound {v : Nat} h : bracketOK v = true : ∀ j : Nat, j j ≠ v := by | | intro j hj | | rw bracketOK, Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | set r := newton v with hr | | have h1' : r r < v := by rwa Nat.blt eq at h1 | | have h2' : v < r+1 r+1 := by rwa Nat.blt eq at h2 | | rcases Nat.lt or ge j r+1 with hle | hge | | · have : j j ≤ r r := Nat.mul le mul by omega by omega | | omega | | · have : r+1 r+1 ≤ j j := Nat.mul le mul hge hge | | omega | | | | end D | | | | namespace D | | | | /- notation bridges -/ | | theorem mul eqn a b : Nat : Nat.mul a b = a b := rfl | | theorem add eqn a b : Nat : Nat.add a b = a + b := rfl | | theorem sub eqn a b : Nat : Nat.sub a b = a - b := rfl | | theorem div eqn a b : Nat : Nat.div a b = a / b := rfl | | theorem mod eqn a b : Nat : Nat.mod a b = a % b := rfl | | theorem pow eqn a b : Nat : Nat.pow a b = a ^ b := rfl | | | | /- the three square masks -/ | | def Q1 : Nat := 7425 | | def Q2 : Nat := 10829 | | def Q3 : Nat := 12673 | | def M1 : Nat := 686103302721484920049784535050278954534677165827919252745428906589397610781403748104863803239426005484700745101610449873073473421444928003015263055170878949005173841803275522550072919609922412523008037032501122741658911671324333538186869565912827742746677748015511977721109522679981442170812370815343229646426424814804315705889565501185328100246520123163266546869227532220453866626165846340275856707262671568288292695235684928266548177726802951534358844948563714309066246164706288302931339771500320438543049156888103224105942127081108664751806025157983170981761977618340678495614039614751395654801267769086465025829996161858315714400497457909797553580429705443184188389216387963490344534950897117664762052732962216653615739477570581879112169912731337636329956723945960116126864260907931625867848086724829768582149207209978622744970702581881439147507363489476590168180456991369192420573604176384666695947525171711374716940593921130678183950911081620154806084413598468648402943210519961713520682908531554006248706845296044915889231636671306336452163098271046455274802855752614126796357410282290627933800458507864254374005922201902980939538828523565714326038105941489075255286574398414822569992986580104867532102105319141758827536991468966430402931141243970240212440783443393710917201120655285082428798987493728740406321949332861418880496853145751712175589481016329677375531778654220117223248995988223585228800780717388608562435497496825840342428296648816382055020965041456284120564430912096531040890135869566832700245235734818269170616058529480998368408566063881388503903670579546013119653848078355409375117804677807652709940241490686339361060122547030328931593171727211195594977888398732581275540829953356918417926013984772384523234222520387411094099175136693566460701499145810135771558529522034798156957433280153711141607942661900116004730914817693178571621886626980624878757126859460087932417307847538166477253282301565262845332494084507857827930548626633901977821799812544724348865676216559103984268617584265363709859671603984158485722515910695015386826667554242903259912550633526151394127650952010132846663263717151106456540902143033290898214473449813922550691488934846018857923816304703593067961582388677240502346714257165451795 | | def M2 : Nat := 9264285825709764424947275326872284218472489723701999803466798958773587569803254819216805461363429131954602391859906418171695008296907085982884795789873768597145240075977796845075402296321578269015488885995546273978976235012266536741617740608594195503064787342556554361760527788716374608785968945306674226871194178965936533435245091677751513658759107934304589452904100410369815562754116638887429253214502354493452907625987263032376110445639397861507915047726130790283975510660531855471206295670928399461243575618823380980022663513366763769037577864448152252221529103584046368992535649062075647458893416049778149269542317631760319231495808906594359863399702982276921833667340708611541154142989154174406121632112431589154378007435403600245827665648101941737322869021342229855412115608319362650850009235252150245934151447060259632190124026513350359068983322519720251960231115463390044798394602990681469544912282963574134526941969056897742005629023598321809205947865170960741762624669085471604411934747654512851661832599148868035396092649853228330469131009865225121059294787693187615025400296540081491772941833027360712257009203626269709520962894586093629756187978300279395086859861324840200564252646268463734485962340696478234278173040055657772959576175529902181243529546558432445442208926337516783935751797449013920339867347684040042414713107414480435785883143906590718116827124998483918198958733682503929503889753703026281124942160616380486038090434784809711861243108951991315948347893221589899560289790650127196314708298825238121091061742437865787734018003588124416081841969102059649583821722694668161161390653298960018896733741591584147055441459179624149287642462292694790596520946646204033794555156874412832176605737123167423815761887001583063664034130147338804398627283318842608179854586067155434424996129479292629882536443507170597035758578280964597265432179305037989238718407902466988335587536999328411731315968724758541284772561915329073746455672554238506372846605397945135799658316861279873652460230320253125666348078353068161321447811813298575678114700138052930056282919876070391522666307351627303572286770689371491263042802506600827181225524889318615726782565310646948868448589203381746993326044686451215125934481708415608849260007250044119996024372972062890155224533928754653707981692925254563773447750349313793480773131576757713736734059855844717102459671763754002596036282528422662017635046497481252351402329347639206124290396664487994815827060472273111455783239203067852928309218513443519090350193563014542392062541569163251247779788563984564267097782413533319463708558783210371245821123381916919323457210248995481008159179910850995952229830215426065053010678846773777272458165910846721991242111018288335282843396202109592762159643829138167946705971597292847817895165011690068328733424137249535185882758846728485460676566631425048289706700845181980226339848682577357082790772058933515264912968131206365358271812274741481322060939130958103741326126875739522142940774386764742570870540558358344549590538236676332449374259084679122986576288743709342640232295995978686311478557184479164097121786129023165002594791573177398934906169876512293137210674287980525747667076582020078935015630249168021744046190101408671405075121530063731898322147306701331 | | def M3 : Nat := 2141902700066056757219862849492302458996434288059756413253410026125667946342068821219223542566745538110447840623049776772256307741190397635083513971046615796044256803754696853912769724128051862616313490634703134802019789502043553366753327435698706413877962013115327599685562236752108687385713480748075682857836632576784105039759369570854079179130003209305774467414872672483452101318864308631608481279649970833685586972783356088770214525882986777087913124029569980281271259261 j hj | | | false = | | cases h3 : Nat.beq Nat.land Nat.shiftRight K3 Nat.mod v R3 1 0 with | | | true = exact beq land zero maskK3 all h3 j hj | | | false = | | cases h4 : Nat.beq Nat.land Nat.shiftRight K4 Nat.mod v R4 1 0 with | | | true = exact beq land zero maskK4 all h4 j hj | | | false = | | rw sqTest2, h2, h3, h4, cond false, cond false, cond false at h | | exact bracketOK sound h j hj | | | | /- 4-ary tree -/ | | | | def allB4 p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | p | | fun f ih a = | | let s := Nat.pow 4 f | | ih a .and ih Nat.add a s .and ih Nat.add a Nat.mul 2 s .and ih Nat.add a Nat.mul 3 s | | fuel | | | | theorem allB4 sound {p : Nat → Bool} : ∀ f : Nat a : Nat , allB4 p f a = true → | | ∀ i, a ≤ i → i < a + 4^f → p i = true := by | | intro f | | induction f with | | | zero = | | intro a h i h1 h2 | | have : i = a := by omega | | simpa this using h | | | succ f ih = | | intro a h i h1 h2 | | have hs : allB4 p f+1 a = allB4 p f a .and allB4 p f a + 4^f .and | | allB4 p f a + 2 4^f .and allB4 p f a + 3 4^f := by | | show let s := Nat.pow 4 f; | | allB4 p f a .and allB4 p f Nat.add a s .and allB4 p f Nat.add a Nat.mul 2 s .and | | allB4 p f Nat.add a Nat.mul 3 s = | | simp only add eqn, mul eqn, pow eqn | | rw hs at h | | simp only Bool.and eq true at h | | obtain ⟨h0, hh1, hh2, hh3⟩ := h | | have hp : 4:Nat ^ f+1 = 4 4^f := by rw Nat.pow succ ; omega | | rcases Nat.lt or ge i a + 4^f with c1 | c1 | | · exact ih a h0 i h1 c1 | | rcases Nat.lt or ge i a + 2 4^f with c2 | c2 | | · exact ih a + 4^f hh1 i c1 by omega | | rcases Nat.lt or ge i a + 3 4^f with c3 | c3 | | · exact ih a + 2 4^f hh2 i c2 by omega | | · exact ih a + 3 4^f hh3 i c3 by omega | | | | | | /-- hybrid: covers a, a + 2^fx using 4-ary subtrees. -/ | | def allBH p : Nat → Bool fx a : Nat : Bool := | | cond Nat.beq Nat.mod fx 2 0 | | allB4 p Nat.div fx 2 a | | allB4 p Nat.div fx 2 a .and allB4 p Nat.div fx 2 Nat.add a Nat.pow 2 Nat.sub fx 1 | | | | theorem allBH sound {p : Nat → Bool} fx a : Nat h : allBH p fx a = true : | | ∀ i, a ≤ i → i < a + 2^fx → p i = true := by | | intro i h1 h2 | | rw allBH at h | | cases hb : Nat.beq Nat.mod fx 2 0 with | | | true = | | rw hb, cond true at h | | rw Nat.beq eq at hb | | simp only mod eqn at hb | | have h4 : 4:Nat ^ Nat.div fx 2 = 2^fx := by | | simp only div eqn | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | exact allB4 sound a h i h1 by omega | | | false = | | rw hb, cond false at h | | rw Bool.and eq true at h | | obtain ⟨ha, hb2⟩ := h | | have hbn : fx % 2 ≠ 0 := by | | intro hcon | | rw show Nat.mod fx 2 = fx % 2 from rfl, hcon at hb | | simp at hb | | have h4 : 4:Nat ^ Nat.div fx 2 = 2^ fx-1 := by | | simp only div eqn | | rw show 4:Nat = 2^2 from rfl, ← Nat.pow mul | | congr 1 | | omega | | have he : Nat.add a Nat.pow 2 Nat.sub fx 1 = a + 2^ fx-1 := by | | simp only add eqn, pow eqn, sub eqn | | rw he at hb2 | | have hsplit : a + 2^fx = a + 2^ fx-1 + 2^ fx-1 := by | | have hpow : 2:Nat ^fx = 2^ fx-1 + 2^ fx-1 := by | | obtain ⟨k, rfl⟩ : ∃ k, fx = k+1 := ⟨fx-1, by omega⟩ | | simp only Nat.add sub cancel, Nat.pow succ | | omega | | omega | | rcases Nat.lt or ge i a + 2^ fx-1 with c1 | c1 | | · exact allB4 sound a ha i h1 by omega | | · exact allB4 sound hb2 i c1 by omega | | | | end D | | | | namespace D | | | | /- final optimized leaf + trees v4 -/ | | | | def leafX4 A8 x : Nat : Bool := | | let t := Nat.mul x Nat.add x 3 | | let c := Nat.div Nat.mul t Nat.add t 2 24 | | let v := Nat.sub A8 Nat.mul 8 c | | cond Nat.ble v 1 true | | cond Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 true sqTest2 v | | | | theorem notSquare of tests {v : Nat} | | h : cond Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 true sqTest2 v = true : | | ∀ j : Nat, j j ≠ v := by | | intro j hj | | cases h1 : Nat.beq Nat.land Nat.shiftRight K1 Nat.mod v R1 1 0 with | | | true = exact beq land zero maskK1 all h1 j hj | | | false = | | rw h1, cond false at h | | exact sqTest2 sound h j hj | | | | theorem leafX4 sound {W x : Nat} h : leafX4 8 W+1 x = true : ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | have hc4 := c4 alt x | | rw leafX4 at h | | simp only hc4 at h | | cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | | true = | | rw Nat.ble eq at hb | | simp only sub eqn, mul eqn at hb | | omega | | | false = | | rw hb, cond false at h | | have hlt : ¬ Nat.sub 8 W+1 Nat.mul 8 c4 x ≤ 1 := by | | rw ← Nat.ble eq, hb ; simp | | simp only sub eqn, mul eqn at hlt | | have hv : Nat.sub 8 W+1 Nat.mul 8 c4 x = 2 w+3 2 w+3 := by | | simp only sub eqn, mul eqn | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | rw hv at h | | exact notSquare of tests h 2 w+3 rfl | | | | def xtreeOK4 W : Nat : Bool := | | let fx := Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 | | allBH leafX4 Nat.add Nat.mul 8 W 1 fx 0 .and Nat.ble W c4 Nat.pow 2 fx | | | | theorem xtreeOK4 sound {W : Nat} h : xtreeOK4 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | intro w x heq | | simp only xtreeOK4 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq at h2 | | have ht := t2 ge one w | | have he : Nat.add Nat.mul 8 W 1 = 8 W+1 := by simp only add eqn, mul eqn | | rcases Nat.lt or ge x 2 ^ Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 with hx | hx | | · have hl := allBH sound 0 h1 x Nat.zero le by omega | | rw he at hl | | exact leafX4 sound hl w heq | | · have hc : c4 Nat.pow 2 Nat.add Nat.div Nat.log2 Nat.mul 24 W 4 1 ≤ c4 x := by | | apply c4 mono; rw pow eqn ; exact hx | | omega | | | | def leafY4 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK4 Nat.sub N b | | | | theorem leafY4 sound {N r8 y : Nat} h : leafY4 N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp | | simp only leafY4, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK4 sound h w x this | | | | def ytreeOK4 N fy r8 : Nat : Bool := | | allB leafY4 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | theorem ytreeOK4 sound {N fy r8 : Nat} h : ytreeOK4 N fy r8 = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | simp only ytreeOK4 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY4 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | def leafZ4 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true ytreeOK4 N fy r8 | | | | theorem leafZ4 sound {N fy z : Nat} h : leafZ4 N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ4, hb, cond false at h | | exact ytreeOK4 sound h w x y heq | | | | theorem master4 {N fy fz : Nat} | | h : allB leafZ4 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ4 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | | | <END TOOL OUTPUT | | | | | | 121 --- ASSISTANT --- | | The v4 pipeline is working correctly, so now I'm writing a Python simulator that matches the exact semantics. I need to figure out what t2 w represents—it corresponds to a positive triangular number with the constraint that 8 t2 w + 1 = 2w+3 ^2 , which simplifies to t2 w = w+1 w+2 /2 , making it equivalent to the triangular number T {w+1} for w≥0. | | | | I'm verifying this works: when w=0, I get t2 0 = 1, which matches T 1. For the combinatorial functions, c4 x simplifies to the binomial coefficient C x+3,4 , with c6 and c8 following the same pattern. Now I'm implementing the checker logic with a leaf test that computes a value from the input, then runs it through a series of modular checks using lookup tables before falling back to a Newton-based square test if needed. | | | | Writing checker functions... + 1 else 0, so the logarithm of 1 is 0 and of 0 is also 0. The seed value 2^ log2 v /2+1 is guaranteed to be greater than sqrt v , which is what we need for Newton's method to converge properly. For any v ≥ 2, this approach converges monotonically downward to floor sqrt v — it's a well-known property of Newton's method for integer square roots, and 64 iterations of fuel is more than sufficient since each step roughly halves the error. The seed stays within reasonable bounds even for large values up to 2^64, and the bracketOK check validates the result anyway. Now I'm looking at how xtreeOK4 computes fx as log2 24 W //4. | | | | I need to verify that allBH covers the range x ∈ 0, 2^fx and that W stays within the bound c4 2^fx . The c4 function computes binomial coefficients using the formula c4 x = x x+3 x x+3 +2 /24, which I can verify against the definition in the code. For the fx choice to work, I need to confirm that W ≤ c4 2^fx always holds when fx = floor log2 24W /4 + 1, which gives 2^fx ≥ 2· 24W ^ 1/4 , ensuring c4 2^fx is large enough to bound W. | | | | Now I'm defining a recursive tree structure where leafY4 checks if N fits within a bound computed from r8 and c6 y , falling back to ytreeOK4 if needed. ytreeOK4 then iterates over y values and checks the overall constraint N ≤ r8 + c6 2^fy . Similarly, leafZ4 uses r8 = c8 z and delegates to ytreeOK4, while the master function iterates over z values to ensure N ≤ c8 2^fz . | | | | With fy=9, I'm calculating that c6 512 gives roughly 2.5e13, which handles N values up to that threshold. For fz=8, c8 256 yields approximately 4.6e14, extending the range significantly further. | | | | Now I'm defining the binomial coefficient functions precisely—c6 y = C y+5,6 and c8 z = C z+7,8 —and I'll use math.comb in the simulation for consistency. The kernel cost per x-leaf is around 110 microseconds, and I need to estimate the total number of x-leaves by counting y,z pairs where c6 y + c8 z < N, which for N=6e12 involves summing over z values to get the approximate pair count. So with about 4096 x values per pair and roughly 35,000 pairs, I'm looking at around 140 million leaves total. At the measured rate of 110 microseconds per leaf, that works out to about 4.3 hours of computation time. The summary suggested around 3 hours at a smaller scale, and scaling up to 6 trillion with the power law relationship pushes it closer to 7 hours. | | | | That's getting risky — I'm worried about hitting timeout limits during verification. The mod-225 residue optimization could cut the x enumeration down by 3 to 4 times, which would help significantly. But I'm also wondering if there's a fundamentally better approach here. The real bottleneck is that each leaf takes about 110 microseconds no matter what, so the enumeration cost itself is the limiting factor. I could try swapping the roles — instead of enumerating all possible x values, enumerate w values for each z,y pair using a triangular enumeration. But that would give me around 3.5 million w values, which is actually much worse than the x approach. | | | | Looking at the residue table option with mod 225: for each fixed W residue, I'd compute v = 8 W - c4 x + 1 mod 225, where c4 x follows a periodic pattern. The binomial coefficient C x+3,4 mod 225 has some period related to 2025, and the summary mentions this could be handled with packed lookup tables covering about 455K cases. But that's getting complicated. A simpler alternative would be to tighten the first filter so more x values get rejected early, but that doesn't really help since the enumeration itself is the cost — every x still needs to be checked. | | | | Now I'm questioning whether the 110 microsecond leaf evaluation time is realistic. That would mean roughly 22,000 kernel reduction steps per leaf at 5 microseconds per step, which seems high just for computing t, c, v, the bilinear form, and the K1 shift. The shift operation in particular — shifting a 225-bit constant by v mod 225 — involves recursive division steps that could add up quickly. | | | | But wait, the kernel has GMP-accelerated support for bitwise operations including shiftRight, so that's not the bottleneck. The 110 microsecond cost is probably dominated by tree traversal and closure application overhead rather than the arithmetic itself. So the question becomes whether we can reduce the leaf cost by batching multiple x values per leaf or unrolling the computation. | | | | Each leaf application involves beta-reducing the lambda applied to a literal x value and then evaluating the let-bindings for operations like Nat.mul x x+3 , which takes roughly 20 reduction steps and lands us around 100 microseconds. Batching multiple x values per leaf could share some tree overhead, but each x still needs its own arithmetic operations, so we'd probably only get a 2× improvement at best. | | | | A more promising approach is filtering the x values at generation time using residue classes—for instance, fixing r = W mod 225 and then working with the period of c4 mod 2025 to reduce how many x values we actually need to process. | | | | Now I'm looking at the quadratic residue structure: the K1 test passes when v could be a square, which happens with probability roughly equal to the number of quadratic residues mod 225 divided by 225. Computing the squares mod 9 gives us 4 values, and mod 25 gives us 11 values, so mod 225 we get 4 × 11 = 44 out of 225, or about 19.6%. This means filtering by K1 in advance cuts down the x count by roughly 5×, so we only enumerate x values whose v mod 225 is actually a possible square—that's the real 3-4× speedup we're looking for. | | | | The implementation would need precomputed tables for each residue class mod 2025, which is complex but feasible, with an estimated runtime of 1-1.5 hours at 6×10^12 operations. Alternatively, we could search for a smaller n₀, though the full sieve already verified coverage up to 10^10 across all classes, and class 86 mod 99 the thinnest one has been scanned above 10^10 up to 5.5×10^12, so counterexamples in other classes below that threshold seem unlikely. | | | | While the scan continues as the main bottleneck, I should start writing a Python simulator to verify the exact semantics, generate the final Spec.lean, and design the mod-225 optimization in Lean with soundness guarantees—since the kernel verification time at n₀ around 6×10^12 or higher could easily exceed a reasonable timeout without aggressive reduction, and a 5× speedup from this optimization could bring it down to 1.5-2 hours plus potential batching improvements. | | | | For the residue-filtered x enumeration with fixed A8 = 8W+1, I need to skip x values where the mod-225 check indicates v is not a square, but the Lean proof must soundly justify this by showing that for every skipped x and every w, the equation t2 w + c4 x ≠ W holds—relying on the fact that v mod 225 being a non-square mod 225 implies v is not a square overall, so no solution exists. | | | | Now I'm checking whether c4 x mod 225 is periodic with period 2025, which would let me use a lookup table approach. The key is verifying that C x+3, 4 mod 225 repeats every 2025 values, and then handling the natural number subtraction carefully in the Lean proof—when A8 < 8·c4 x , the subtraction clamps to 0, but the leafX4 guard on v ≤ 1 already filters those cases. | | | | For the actual proof, I need to show that for each y, z pair, the allowed residue set modulo 225 is consistent, since A8 mod 225 varies per pair. This suggests building a generic mechanism that works across all valid y, z configurations. | | | | I'm thinking about using a stride enumeration approach: instead of checking every x directly, I enumerate pairs q, i where x = 2025·q + srt i , with srt being the sorted list of allowed residues for the current A8 class. For each residue class of A8 mod 225, I count how many x₀ in 0, 2025 satisfy the condition that A8 − 8·c4 x₀ mod 225 is a quadratic residue. This gives roughly 397 allowed residues per class out of 2025, so the total evaluations scale as about 0.196·xmax. The soundness argument requires showing that if the leaf check passes for all q < Q and all i < L, then the overall property holds. | | | | For the completeness check, I need to verify that residues outside the allowed set properly fail the kernel test over the 2025 x₀ values, though I'm working through how to handle the natural number subtraction cleanly. A cleaner approach might be to reparametrize using u = 8·c4 x + s mod 225 to avoid subtraction clamp issues, and define intermediate values like d = c4 x mod 225 to track the modular arithmetic more directly. | | | | Now I'm setting up a skip-lemma that classifies pairs a, e where a is A8 mod 225 and e is x mod 2025, defining when the kernel bit test fails for a given residue class, which would then imply all x in that class satisfying the constraint 8 c4 x ≤ A8 are excluded from the solution set. | | | | Rather than proving individual lemmas per a-class, I'm consolidating into a single decision function that encodes all 455,625 possible a, e pairs and precomputes which ones pass the skip test, with each case requiring just a few arithmetic operations—totaling around 25-45 seconds for the full kernel computation, which is acceptable. | | | | I'm storing the valid e-values for each a-residue as a bitmask in a lookup table roughly 137KB of literal data , then during leaf enumeration in Lean, I iterate through the y, z pairs, extract the a-value, look up its mask, and enumerate only the e-positions where the bit is set—though Lean's tree enumeration makes it tricky to efficiently enumerate just the set bit positions. | | | | The key insight is to flip the loop order: iterate over all 2025 possible e-values in the outer loop creating a tree of depth ~11 , and for each e, check if its bit is set in the mask—if not, the leaf is trivially true, otherwise it runs the inner loop over q-values. | | | | But the cost analysis shows this doesn't actually help: enumerating all 2025 e-values per y,z pair costs roughly 0.22 seconds per pair, which across 35,000 pairs balloons to 7700 seconds—far worse than the current approach. The overhead only becomes worthwhile when xmax is much larger than 2025, but at the problem sizes we're dealing with N around 6e12 to 2e13 , xmax only reaches 3500-4600, barely 2× the period. So residue filtering modulo 225 with a period of 2025 doesn't actually provide a meaningful speedup at these scales, contradicting the earlier estimate of 3-4× improvement. | | | | I'm exploring whether a smaller modulus like 9 could work better instead. Squares modulo 9 only take values {0,1,4,7}, so about 44% of candidates pass the filter. The period of C x+3,4 modulo 9 appears to be around 81, which would mean enumerating just 81 skip-leaves per pair. This saves roughly 2.25× on the filtering cost, bringing the x-evaluations down from 4096 to around 1800 plus overhead from the smaller enumeration. | | | | Combining moduli 9 and 25 together doesn't work well since their periods don't align nicely—the combined period would exceed the search range. A two-level approach might work instead, using the mod 9 filter as an outer loop to reduce the search space before applying other tests. | | | | A more promising angle is batching multiple x values together to amortize the tree traversal overhead. If I process 4 consecutive x values with a shared computation, the per-x cost drops significantly—maybe 1.7× speedup from batching alone, which combined with the mod 9 pruning could reach around 3.5× total. But I should verify the actual constraints and run a careful simulation to count the exact number of evaluations needed. Defining a generic interval tree that recursively splits ranges without the overshoot factor, using fuel-bounded recursion to handle arbitrary interval sizes more efficiently. The overshoot penalty is modest—around 26% extra cost at overshooting nodes, which is minor compared to potential savings from batching or other optimizations. My immediate priorities are running a simulator to get exact leaf counts for candidate N values in the range of 5.5e12 to 2e13, then benchmarking actual per-leaf timing at realistic word sizes to refine the cost model. After that I'll evaluate whether batching which is straightforward to verify and modulo-81 skipping which needs a table lemma are worth implementing. Independent verification of the final n0 value is critical. Now I'm building a Python simulator to compute exact leaf counts... | | | | Writing simulator code... | | The v4 pipeline is confirmed. Now I'll write the Python simulator, starting with the constant definitions for R1–R4, K1–K4, and c4/c6/c8. | | bash | | | | sed -n 700,760p /workspace/leanproject/Dev/Checker.lean | grep -n "def R\|def K" ; grep -n "^def t2\|^def c4\|^def c6\|^def c8\|^def p4\|^def p6\|^def p8" /workspace/leanproject/Dev/Checker.lean; sed -n '/^def t2/,/^theorem t2 ge one/p' /workspace/leanproject/Dev/Checker.lean | head -40 | | | | | | 121 --- TOOL bash --- | | 18:def R1 : Nat := 225 | | 19:def R2 : Nat := 539 | | 20:def R3 : Nat := 221 | | 21:def R4 : Nat := 437 | | 22:def K1 : Nat := 134932278415263153289320518902861294585092876492072418360525652499 | | 23:def K2 : Nat := 30112542410578951545921030936162078674344692016917131568265818246077939783472096749940494893321507315275879452316783821055757733363335518344648930578722944289299 | | 24:def K3 : Nat := 1902691931378299041757545416576313148667104431336290058356702519827 | | 25:def K4 : Nat := 380006767722538127746873153178912511557101225749667469109215699828894109610685345234892465202245680870615963953941297072347087443 | | 43:def t2 w : Nat : Nat := Nat.div Nat.mul Nat.add w 2 Nat.add w 1 2 | | 44:def p4 x : Nat : Nat := Nat.mul Nat.mul Nat.mul x Nat.add x 1 Nat.add x 2 Nat.add x 3 | | 45:def c4 x : Nat : Nat := Nat.div p4 x 24 | | 46:def p6 y : Nat : Nat := | | 48:def c6 y : Nat : Nat := Nat.div p6 y 720 | | 49:def p8 z : Nat : Nat := | | 51:def c8 z : Nat : Nat := Nat.div p8 z 40320 | | def t2 w : Nat : Nat := Nat.div Nat.mul Nat.add w 2 Nat.add w 1 2 | | def p4 x : Nat : Nat := Nat.mul Nat.mul Nat.mul x Nat.add x 1 Nat.add x 2 Nat.add x 3 | | def c4 x : Nat : Nat := Nat.div p4 x 24 | | def p6 y : Nat : Nat := | | Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul y Nat.add y 1 Nat.add y 2 Nat.add y 3 Nat.add y 4 Nat.add y 5 | | def c6 y : Nat : Nat := Nat.div p6 y 720 | | def p8 z : Nat : Nat := | | Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul z Nat.add z 1 Nat.add z 2 Nat.add z 3 Nat.add z 4 Nat.add z 5 Nat.add z 6 Nat.add z 7 | | def c8 z : Nat : Nat := Nat.div p8 z 40320 | | | | theorem t2 def w : Nat : t2 w = w+2 w+1 /2 := rfl | | theorem p4 def x : Nat : p4 x = x x+1 x+2 x+3 := rfl | | theorem c4 def x : Nat : c4 x = p4 x / 24 := rfl | | theorem p6 def y : Nat : p6 y = y y+1 y+2 y+3 y+4 y+5 := rfl | | theorem c6 def y : Nat : c6 y = p6 y / 720 := rfl | | theorem p8 def z : Nat : p8 z = z z+1 z+2 z+3 z+4 z+5 z+6 z+7 := rfl | | theorem c8 def z : Nat : c8 z = p8 z / 40320 := rfl | | | | theorem t2 ge one w : Nat : 1 ≤ t2 w := by | | | | | | 122 --- ASSISTANT --- | | I need to write a Python simulator that implements the master4 check with precise semantics, tracking metrics like total x-leaf evaluations, K1 failures, sqTest2 calls, bracket calls, and overall validity, plus a cost model to analyze performance. | | bash | | | | cat /tmp/sim.py <<'EOF' | | Exact simulator of Dev/Checker.lean v4 pipeline | | import sys | | R1,R2,R3,R4 = 225,539,221,437 | | K1 = 134932278415263153289320518902861294585092876492072418360525652499 | | K2 = 30112542410578951545921030936162078674344692016917131568265818246077939783472096749940494893321507315275879452316783821055757733363335518344648930578722944289299 | | K3 = 1902691931378299041757545416576313148667104431336290058356702519827 | | K4 = 380006767722538127746873153178912511557101225749667469109215699828894109610685345234892465202245680870615963953941297072347087443 | | | | def c4 x : return x x+1 x+2 x+3 //24 | | def c6 y : return y y+1 y+2 y+3 y+4 y+5 //720 | | def c8 z : return z z+1 z+2 z+3 z+4 z+5 z+6 z+7 //40320 | | def log2n v : Nat.log2 | | r=0 | | while v =2: v//=2; r+=1 | | return r | | | | class St: pass | | S=St ; S.xleaf=0; S.k1pass=0; S.sq2=0; S.brk=0; S.pairs=0; S.overshoot=0 | | | | def newton v : | | g = 2 log2n v //2+1 ; fuel=64 | | while fuel 0: | | g2= g+v//g //2 | | if g2<g: g=g2; fuel-=1 | | else: return g | | return g | | | | def bracketOK v : | | S.brk+=1 | | r=newton v | | return r r<v and v< r+1 r+1 | | | | def sqTest2 v : | | S.sq2+=1 | | if K2 v%R2 &1==0: return True | | if K3 v%R3 &1==0: return True | | if K4 v%R4 &1==0: return True | | return bracketOK v | | | | def leafX4 A8,x : | | S.xleaf+=1 | | t=x x+3 ; c=t t+2 //24 | | v=A8-8 c | | if v<0: v=0 Nat.sub clamp | | if v<=1: return True | | if K1 v%R1 &1==0: return True | | S.k1pass+=1 | | return sqTest2 v | | | | def xtreeOK4 W : | | S.pairs+=1 | | fx=log2n 24 W //4+1 | | if not W<=c4 2 fx : return False coverage | | for x in range 2 fx : | | if not leafX4 8 W+1,x : return False | | return True | | | | def leafY4 N,r8,y : | | b=r8+c6 y | | if N<=b: return True | | return xtreeOK4 N-b | | | | def ytreeOK4 N,fy,r8 : | | if not N<=r8+c6 2 fy : return False | | for y in range 2 fy : | | if not leafY4 N,r8,y : return False | | return True | | | | def leafZ4 N,fy,z : | | r8=c8 z | | if N<=r8: return True | | return ytreeOK4 N,fy,r8 | | | | def master4 N,fy,fz : | | if not N<=c8 2 fz : return False | | for z in range 2 fz : | | if not leafZ4 N,fy,z : return False | | return True | | | | if name ==" main ": | | N=int sys.argv 1 ; fy=int sys.argv 2 if len sys.argv 2 else 9; fz=int sys.argv 3 if len sys.argv 3 else 8 | | ok=master4 N,fy,fz | | print "N",N,"result",ok | | print "pairs",S.pairs,"xleaf",S.xleaf,"k1pass",S.k1pass,"sq2",S.sq2,"bracket",S.brk | | print "est kernel time @110us/leaf: %.0f s"% S.xleaf 110e-6 | | EOF | | echo done | | | | | | 122 --- TOOL bash --- | | done | | | | | | 123 --- ASSISTANT --- | | I need to test the simulator with known cases—first checking a value that should fail like N=23343989 where the count is 1, so master4 should return False, and also testing edge cases like N=0 which should return True based on the logic flow. Then I'll time how long the run takes. | | | | For larger values around 5.5e12, computing exact leaf counts through Python iteration would be prohibitively slow with millions of leaf calls, so instead I'll calculate leaf counts analytically by summing powers of 2 over the z,y pairs—a much faster approach with only about 35K pairs to iterate through. I'll also build a C-side verifier to check candidates independently. | | | | The plan is to run the simulator on the known false case, use the fast analytical counter for estimates at 6e12, 1e13, and 2e13, and validate everything with a C implementation using the same semantics. | | bash | | | | cd /tmp && python3 sim.py 23343989 9 8; echo ---; python3 - <<'EOF' | | fast leaf-count estimator no x loop | | from sim import c4,c6,c8,log2n | | def count N,fy=9,fz=8 : | | tot=0; pairs=0 | | assert N<=c8 2 fz | | for z in range 2 fz : | | r8=c8 z | | if N<=r8: continue | | assert N<=r8+c6 2 fy , N,z | | for y in range 2 fy : | | b=r8+c6 y | | if N<=b: continue | | W=N-b | | fx=log2n 24 W //4+1 | | assert W<=c4 2 fx | | pairs+=1; tot+=2 fx | | return pairs,tot | | for N in 5527622910038, 8000000000000, 13000000000000, 20000000000000 : | | p,t=count N | | print N, "pairs",p,"xleaves",t,"est h @110us: %.2f"% t 110e-6/3600 | | EOF | | | | | | 123 --- TOOL bash --- | | N 23343989 result False | | pairs 1331 xleaf 308426 k1pass 25636 sq2 25636 bracket 249 | | est kernel time @110us/leaf: 34 s | | --- | | 5527622910038 pairs 55492 xleaves 222783744 est h @110us: 6.81 | | 8000000000000 pairs 61877 xleaves 250172416 est h @110us: 7.64 | | 13000000000000 pairs 71509 xleaves 438155264 est h @110us: 13.39 | | 20000000000000 pairs 81157 xleaves 586936320 est h @110us: 17.93 | | | | | | 124 --- ASSISTANT --- | | The current measurements show this is way too slow — 6.8 hours at one scale and 13 hours at another. I need a 5-10× speedup to hit my target of 1-2 hours. The bottleneck seems to be the per-leaf cost at around 110 microseconds, which involves applying operations to literals and computing things like multiplication and addition on large numbers through the kernel. I should focus on reducing that overhead first. | | | | Batching multiple x-values per leaf could help by sharing the delta/beta unfolding and tree traversal costs, then unrolling the test expression inline for each x in the batch. With a batch size of 8, I might get the per-x cost down to 40-50 microseconds if I can isolate how much time is spent on arithmetic versus structural overhead. But realistically, batching probably only gets me a 2× speedup since the arithmetic steps per x don't change much. | | | | The real inefficiency is that I'm scanning all possible x-values for every y,z pair, which is the fundamental bottleneck. I need a smarter mathematical approach — maybe a meet-in-the-middle strategy to reduce the search space. | | | | Alternatively, I could restructure the loops entirely: instead of fixing z,y and scanning x, I could fix z,x and loop over y, then apply a mod-225 pre-filter to skip invalid y-values more efficiently. The period-2025 filter doesn't align perfectly with the x-range of 4096, but reordering the loops might let me exploit the filter better. | | | | The real bottleneck is finding a modulus with a short period—something like 16 or 64—where the binomial coefficient C x+3,4 mod q cycles quickly enough that I can bake the skip pattern directly into the enumeration without expensive per-pair overhead. | | | | Testing q=16 doesn't work because all odd values hit squares mod 16, making the filter useless. With q=9, I get a 4/9 pass rate and a period around 81, which is still too long. Let me check q=5 next, where the period of C x+3,4 mod 5 should be more manageable. So the v mod 9 constraint depends on c4 and x mod 9, which stays constant within each column e. This gives a pass rate of 4/9, meaning roughly 1900 evaluations out of 4096 — about a 2.15× speedup, bringing the estimate down to 3.2 hours. That's still not ideal. I'm considering a two-level approach using q=225 instead, restructuring to enumerate z, y, e mod 2025 globally with tiny inner x-loops, though the overhead of evaluating skip conditions for each of the 2025 values of e might dominate the savings. | | | | The real bottleneck is that skip-leaves still require checking a bit in a lookup table for each candidate. Instead of that, I could precompute and store the allowed residues directly — for each residue class a, I'd encode roughly 400 allowed values as a packed literal using about 11 bits per residue, then use a selection function to extract the i-th allowed residue for class a on demand. This shifts the cost from bit-checking to unpacking, and lets me enumerate only valid e values rather than filtering all 2025 or 4096 candidates. | | | | The leaf count drops dramatically: with K = 2 or 3 depending on xmax , I get around 794 to 1191 leaves instead of 4096 — a 3.4× to 5× improvement. For soundness, I'd verify the completeness lemma by checking all 455K cases where membership in the residue list is computable via a complementary bitmask, linking the bit representation to the actual enumerated values. | | | | Now I'm reconsidering the architecture: instead of relating two separate structures, I could prove completeness directly on the SEL enumeration itself — for any residue class a and element e, if the column test says e might contain squares, then e must appear in the SEL list. The challenge is that existence via decision procedure requires search, so I'm exploring whether a counting or monotonicity argument works better, or if I should pivot to covering the x-space via unions of arithmetic progressions instead. | | | | The key insight is flipping the approach: rather than proving the residue list is complete per class, I enumerate all 2025 residues but make the skip decision cheap by applying a bit test on a precomputed table — testing whether a particular residue should be skipped costs just a couple GMP operations on the 2025-bit number plus a conditional, roughly 40-60 microseconds versus 110 for a full leaf evaluation, which brings the overall cost down significantly. | | | | However, the per-pair baseline of 450 milliseconds only drops to 188 milliseconds with this optimization — a 2.4× improvement that's still limited by the e-loop overhead. To push further, I'm considering a 4-ary pretest tree where each node checks four residues at once using a bitmask test, skipping entire subtrees when all four residues should be skipped; with random clustering of skippable residues around 20%, the probability of four consecutive skippable residues is roughly 0.41, which could meaningfully reduce iterations. | | | | I'm also exploring whether precomputing the L a lists outside Lean and embedding explicit x-lists in the file could help, though the Lean proof would still need to verify completeness — checking that no solutions exist for x values outside the list, which is the hard direction and likely requires interval arithmetic. A different angle: instead of looping over x to check if v = 8 W − c₄x + 1 is a square, I could flip the logic and scan through known squares to find valid x values, checking whether 8c₄x + u² = 8W for odd squares u ≥ 3. | | | | The enumeration approach hits a wall though — with u ranging up to roughly 6.6 million at W ≈ 5.5 × 10¹², there are too many candidates. But I'm noticing that v mod 5 has a period of 25 in x, so I'm designing a multi-level tree structure where x decomposes as 2025k + 81b + e, using modular residue tests at different levels to prune the search space — the idea is that c₄x mod 9 has period 81 and c₄x mod 225 has period 2025, so I can build a 3-level tree with bit tables to skip invalid branches early. | | | | The challenge is that when I drill down into the middle level x = 81m + e with m < 51 , the period of c₄x mod 25 as a function of m might be 125, which is larger than my m-range, creating the same recursive bottleneck. I'm realizing I need to compute the actual periods numerically using Kummer's theorem — for binomial coefficients mod p^a, the period is p^ a + ⌊log p k⌋ , so for C x+3, 4 mod 9 with p=3, a=2, k=4, the period should be 3^ 2+1 = 27, and mod 225 it's more complex. | | | | With period 27 mod 9, I still get 4/9 passing, so about 1820 evaluations plus 27 skip-leaves. For mod 5, the period of c₄ is 25, and combining mod 45 gives lcm 27, 25 = 675 with a pass rate of 4/9 × 3/5 ≈ 0.267, meaning I can skip most of the 4096 range using a 675-bit mask. | | | | The combined mod 45 approach brings this down to around 1430 evaluations—roughly 2.9× speedup—but adding mod 7 would require a period of 33075, which is too long to be practical. The realistic gains from residue skipping max out around 2–3× because skip-leaf checks themselves have a cost and the periods are already comparable to the search range. | | | | I'm now thinking about packing the K-column masks more densely so a single GMP operation can test whether multiple columns are skippable at once. For class a, I can represent the table as a bitmask where positions with bit 0 can be skipped, then build a sparse tree where each node tests whether all leaves in its subtree are skippable with one bit-extract operation. With roughly 73% zeros randomly distributed, about 28% of 4-blocks and 53% of 2-blocks would be all-zero. The expected number of full-leaf evaluations per period is around 180, and skip-tests would be roughly 360 nodes visited—which ends up being about the same cost as before, so the gains are marginal. | | | | Now I'm considering whether there's a cheaper certificate for verifying that certain values aren't quadratic residues. The kernel would need to compute the residue for each candidate, which is at least 4-6 GMP operations per value, translating to roughly 20-30 microseconds each. For 4096 candidates, that's a floor of about 100 milliseconds per pair, or around 5540 seconds total. | | | | With 55,000 pairs, that's roughly 1.5 hours even at the theoretical minimum. I can push below that by using modular filtering with residue lists to skip most pairs upfront — with a pass rate of 0.196, I'd get down to 25-35 milliseconds per pair, or about 30 minutes total. The tradeoff is needing to build and verify the completeness of those residue lists once. | | | | The next optimization is to apply the same residue-based filtering to skip entire y,z pairs, not just individual values. | | | | On parallelism: I'm wondering if Lean can split the work across multiple theorems or declarations. The file has to be submitted as one piece, and Lean elaborates decide theorems sequentially within a single file. Lean 4.27 should have parallel elaboration of theorem bodies enabled by default since version 4.19 or so, though the summary suggests no async elaboration is happening here. | | | | The kernel checking might be the bottleneck — even if elaboration runs in parallel, the kernel work happens at elaboration time inside Decide.decide , and that could be serialized. I'm thinking of testing this directly: create a file with four theorems each taking ~10 seconds with decide +kernel , then measure wall time. If parallelism is working, it should take around 10 seconds total instead of 40. The summary claims to have tested this already, but maybe the test wasn't set up right — perhaps the theorems had dependencies or shared computation. If 16× parallelism is actually available, that would solve the time problem entirely. | | | | I should also check whether Lean 4.19+ has the Elab.async option enabled by default, since that controls whether proofs get checked in parallel tasks. My test plan would be to create a file with eight distinct heavy theorems using decide +kernel , then time the elaboration. If async mode is working properly, the wall time should scale with the number of cores available, not linearly with the number of theorems. | | The kernel times are too high at 6.8 hours, so I'm going to carefully re-test whether Lean 4.27's async elaboration can parallelize independent theorems—this could be a major win—and explore residue-list optimization if needed. | | bash | | | | cd /workspace/leanproject && cat /tmp/partest.lean <<'EOF' | | set option maxHeartbeats 0 | | def f a : Nat : Nat → Bool := fun n = Nat.ble 1 a + n n n % 7919 + 1 | | def allT p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool p | | fun f ih a = ih a .and ih Nat.add a Nat.pow 2 f fuel | | theorem t1 : allT f 1 17 0 = true := by decide +kernel | | theorem t2 : allT f 2 17 0 = true := by decide +kernel | | theorem t3 : allT f 3 17 0 = true := by decide +kernel | | theorem t4 : allT f 4 17 0 = true := by decide +kernel | | theorem t5 : allT f 5 17 0 = true := by decide +kernel | | theorem t6 : allT f 6 17 0 = true := by decide +kernel | | theorem t7 : allT f 7 17 0 = true := by decide +kernel | | theorem t8 : allT f 8 17 0 = true := by decide +kernel | | EOF | | cat /tmp/partest1.lean <<'EOF' | | set option maxHeartbeats 0 | | def f a : Nat : Nat → Bool := fun n = Nat.ble 1 a + n n n % 7919 + 1 | | def allT p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool p | | fun f ih a = ih a .and ih Nat.add a Nat.pow 2 f fuel | | theorem t1 : allT f 1 17 0 = true := by decide +kernel | | EOF | | time lake env lean /tmp/partest1.lean; echo ========; time lake env lean /tmp/partest.lean | | | | | | 124 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 125 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && nohup bash -c ' time lake env lean /tmp/partest1.lean /tmp/pt1.log 2 &1; time lake env lean /tmp/partest.lean /tmp/pt8.log 2 &1' /dev/null 2 &1 & echo started; tail -2 /tmp/scan99b.err | | | | | | 125 --- TOOL bash --- | | started | | |S3|=348144743 2.79 GB | | block 1/35 done marks=165241602558 zeros=0 | | | | | | 126 --- ASSISTANT --- | | While the first block runs, I should check if machine contention is affecting performance—it's been about 18 minutes since starting around 21:52. For the partest with a single theorem, I'm estimating around 2-3 seconds for the actual computation across ~131k leaves, plus maybe 1 second for Lean startup since there are no imports. Let me wait and see how it progresses, but in the meantime I'll compute the actual periods of c4 modulo 9, 25, and 225 numerically and think through the SEL design. | | While that runs, I'll compute the actual periods of c4 modulo small moduli. | | bash | | | | sleep 60; cat /tmp/pt1.log /tmp/pt8.log 2 /dev/null; python3 - <<'EOF' | | from math import comb | | def per q, P : | | c= comb x+3,4 %q for x in range 3 P | | for p in range 1,2 P : | | if all c x+p ==c x for x in range P : return p | | return None | | for q in 3,9,27,5,25,7,49,11,225,45,15 : | | print q, per q, 3000 | | EOF | | | | | | 126 --- TOOL bash --- | | 3 9 | | 9 27 | | 27 81 | | 5 5 | | 25 25 | | 7 7 | | 49 49 | | 11 11 | | 225 675 | | 45 135 | | 15 45 | | | | | | 127 --- ASSISTANT --- | | The periods are much shorter than I expected—c4 mod 9 gives 27, mod 25 gives exactly 25, and mod 225 surprisingly gives 675 rather than 2025. With xmax around 4096, that's roughly 6 complete periods for the mod 225 case, so I should be able to get a good fraction of the full test coverage. | | | | For mod 225, about 44 out of 225 residues are squares, giving roughly 132 allowed exponents per class. I'm designing a lookup structure where each of the 225 classes stores a list of allowed exponents in the range 0, 675 —roughly 10 bits per entry, totaling around 37KB across all classes. The key insight is that I don't need to check every x; instead, I enumerate through periods and use the precomputed allowed sets, skipping the redundant K1 test since it's already implied by membership in the allowed set. | | | | For soundness, if an exponent e falls outside the allowed set for class a, I rely on a completeness lemma showing that the resulting value v cannot be a square mod 225, which rules out false positives. The lemma connects the bit pattern of the allowed set to the quadratic residue structure, ensuring that any x with a forbidden exponent will correctly return true either by clamping or by failing the square test . | | | | Rather than enumerate allowed exponents as explicit lists, I'm switching to a bitmask-based representation where each of the 225 classes gets a 675-bit mask, then derive membership checks directly from the mask bits using tree-based subtree skipping to avoid iterating all 675 values. | | | | For the decision lemma, I'm defining a fixed lookup table that encodes which exponent-value pairs are valid for each class, using a bit-shift and mask operation to extract the relevant bits—padding all classes to a uniform maximum length around 180 with a harmless duplicate of the first element so extra checks don't break soundness. | | | | The tradeoff is that this fixed-size approach increases evaluations per pair from roughly 0.196·675·K to 200·K, which is acceptable overhead. An alternative would be to store per-class lengths in a separate blob and use variable-size trees, but that complicates the tree structure—though I could make the leaf check quickly return true if the index exceeds the actual class length with just a couple of operations. | | | | The simplest robust solution is to use a fixed Lmax and pad shorter classes by repeating a valid element, so all leaves do full work and the pass fraction becomes Lmax/675. Now I need to reformulate the completeness lemma: instead of a single existential statement, I'll split it into two lemmas—one verifying the mask table TBL directly across all 152K cases, and a second connecting the SEL blob to TBL. | | | | The first lemma checks that whenever TBL has a zero bit, the corresponding square bit is also zero. The second lemma verifies that whenever TBL has a one bit, the membership search over SEL actually succeeds—but that's roughly 30M operations, which might be too slow at 150 seconds. I could avoid the TBL table entirely and express the bounded existential as a Bool-valued search instead, though the cost stays the same. Or I could try inverting the encoding altogether. So the cleaner approach is to store an index blob that maps each a,e pair to an 8-bit value, which lets me verify the completeness condition cheaply: if the square bit is set for g a,e , then that index must point to a valid position in the SEL list that recovers e. This trades a bit of storage around 152K for a decidable certificate that avoids enumerating all the allowed values explicitly. So the SELBLOB would be around 56KB if Lmax is 200, which is manageable. The literal numbers in the file span roughly 150K decimal digits, and GMP handles that fine — the whole file ends up a few hundred KB. Now I need to compute the actual distribution of L a, which counts how many elements e < 675 satisfy the quadratic residue condition modulo 225. Since a = 8W+1 mod 225 and 8 is invertible mod 225, all 225 residue classes appear as W varies, so every class gets represented. | | | | For the filtering strategy, I'm skipping the K1 test mod 225 check since it would typically pass anyway, and jumping straight to K2, K3, K4 tests before bracketing. Looking at the pass rates, about 8.3% of all x-evaluations that pass the v≤1 guard also pass K1, which is lower than expected because the v≤1 cases are pulling the average down. | | | | The key insight is that v mod 225 isn't uniformly distributed across x values—since v = 8 W−c4x +1 and c4x mod 225 has a biased image over the 675-period cycle, the actual pass fraction is lower than the theoretical 19.6% for squares mod 225. This suggests the mean L a could be around 56, and I need to compute the full distribution to estimate the maximum class size for the SEL approach. | | | | For the speedup calculation, I'm working through the enumeration strategy: with K = ceil 2^fx/675 , choosing K=7 for 2^fx=4096 causes a 15% overshoot. A better approach is to set K based on the exact bound where c4 675K ≥ W, then verify coverage for all allowed residue classes within that bound. Computing K deterministically in Lean using a fourth root approximation — I'll apply Newton's method twice to get an approximate fourth root of 24W, then divide by 675 and add 1 to get K. The coverage check validates that c4 675K W holds, so if the check passes, the bound is sound without needing to verify Newton's correctness itself. Newton's method gives exact floor square root when initialized properly, which I can verify at runtime with the comparison operators in the definition. For the i-tree enumeration, I'm iterating over indices j in the range 0, K·2^fL where fL is a fixed log-based tree depth, then decoding each j into the pair k, i by dividing and taking the remainder to extract k and i, with x computed as 675· j fL + S. | | | | Now I'm considering whether to use a single allBH tree covering the full K·2^fL range or split into K separate subtrees. A single tree with total depth fL + ceil log2 K would cover the needed range, but indices beyond K·2^fL would overshoot and incur leaf cost with up to 2× overhead for K in 4, 8 . The alternative is to have the leaf itself check whether k is within bounds. | | | | Adding a cheap guard check 2 ops, ~10-20μs to verify k ≥ K first keeps overshoot to at most 2× on the count, which is acceptable given the cheap-leaf cost adds only ~15% overhead. I could also swap the indexing scheme to j = i·K + k, but that has the same overshoot problem on the i side. Sticking with k-major indexing and the guard is cleaner. | | | | Another option is to pad Lmax up to a power of 2 by choosing fL such that 2^fL ≥ Lmax, then fill the extra SEL entries with a harmless repeated value that passes the full-cost check. The padding overhead is eating up most of the gains—nearly 60% of the useful work in cheap leaves. I could add a per-class length lookup with a guard check to avoid full decoding, but that's still the same padding cost with just a few fewer operations. Generating specialized code per pair would explode the file size with 55K pairs. The real win would be reducing the guard cost itself, but I'm hitting diminishing returns here. | | | | Now I'm realizing the actual bottleneck: extracting each element requires shifting a massive 450-kilobit blob by a large amount, which materializes a huge intermediate result before masking down to the bits I need. That shift operation on 56KB of data is probably taking 5-10 microseconds per extraction, which compounds quickly across many lookups. | | | | The better approach is to extract a class-specific subblob once per pair at the pair level—computing which portion of the blob corresponds to the current class value—then have the leaf just do smaller shifts within that precomputed subblob. This way I'm doing one expensive shift operation per pair instead of per element lookup. Useful leaves all pass the check by construction, so I can skip the K1 test entirely and go straight to K2/K3/K4 bracket operations—sqTest2 already validates that v is non-square directly from the enumerated x values. Per-leaf, I'm looking at decode, guards, selection, extraction of t/c/v, and then sqTest2 which does a 539-bit shift and modular operations. Since K1 never filters useful leaves by construction, they all proceed to K2, K3, and K4. Looking at the measured pass rates, K2 alone rejects most candidates around 1% pass through mod 539 , and the combined effect of all three tests filters out roughly 99% of leaves, with K2 typically being where sqTest2 exits. | | | | Estimating the cost per useful leaf at around 30-35 reductions roughly 130-150 microseconds , I'm seeing that with a mean leaf count of about 56 per pair and K=7, we'd have roughly 390 useful leaves per pair. That works out to about 55 milliseconds per pair including padding overhead, compared to the current 450 milliseconds—roughly an 8× improvement even accounting for the per-leaf reduction costs. | | | | Now I need to verify the pass fraction more carefully. At N=23M with about 308K x-evaluations and 25K passing K1, the pass rate among v 1 cases is closer to 8.6%, and I should compute the exact L a distribution to confirm whether the mean of 58 and potential max over 100 hold up. The pair-level overhead for computing parameters and coverage checks is negligible at around 70 microseconds, so scaling to N=5.5e12 with roughly 55K pairs should still be manageable. | | | | Rechecking the timing: 55K pairs at 450ms each gives about 6.9 hours, which matches my earlier estimate. With the refined mean useful work per pair at around 336 operations and accounting for skipped columns only in full-column cases, I'm looking at roughly 52 milliseconds per pair, bringing the total down to about 53 minutes for the full run. | | | | At the larger scale of 1.3e13 operations, scaling by the time complexity factor gives around 76 minutes, which is acceptable. Before implementing, I need to verify the modulo-675 structure empirically by computing the actual L a distribution and confirming the speedup on the real simulator, plus reviewing the partest results and point logs. | | I found that c4 mod 225 has a period of 675 in x, which is shorter than expected. Now I'll compute the exact per-class allowed-residue distribution and check the parallelism test. | | bash | | | | cat /tmp/pt1.log /tmp/pt8.log 2 /dev/null; echo ====; python3 - <<'EOF' | | from math import comb | | sq225 = set j j %225 for j in range 225 | | class a = 8W+1 % 225 ; allowed e in 0,675 : a - 8 c4 e % 225 in sq225 | | c4m = comb e+3,4 %225 for e in range 675 | | Ls= | | for a in range 225 : | | L = sum 1 for e in range 675 if a - 8 c4m e %225 in sq225 | | Ls.append L | | import statistics | | print "mean",statistics.mean Ls ,"min",min Ls ,"max",max Ls | | print sorted Ls ::20 | | how many classes actually occur? a = 8W+1 %225 for W arbitrary - all | | EOF | | | | | | 127 --- TOOL bash --- | | | | real 1m12.480s | | user 0m17.487s | | sys 0m0.883s | | ==== | | mean 132 min 0 max 425 | | 0, 0, 32, 40, 44, 68, 85, 160, 200, 275, 340, 425 | | | | | | 128 --- ASSISTANT --- | | Looking at the timing data from pt1.log — 72 seconds wall time but only 17 seconds user time is a red flag. The huge gap suggests the machine is heavily contended with other processes load at 88 , which is problematic for reliable benchmarking. The user time of 17 seconds for processing 131,072 leaves seems roughly consistent with expected overhead, but I need to figure out what's causing the wall time to balloon so much — possibly lake rebuilding something in the background despite running "lake env lean." | | | | Now examining the L a distribution: mean is 132 matching the theoretical 675 × 0.196 , with a max of 425 and surprisingly a min of 0. The observed 8.3% pass rate doesn't match the theoretical 19.6% mean, which suggests the distribution of which classes actually occur in practice isn't uniform. The W distribution varies with the y,z pairs, so different classes appear with different frequencies. I'm also noticing that overshooting beyond xmax accounts for roughly 30% of evaluations, and among the actual valid x values, the pass rate comes out closer to 11.9% — still below the theoretical mean. With only 1331 pairs at N=23M, sample sizes are small, but the key insight is that the mean L across classes that actually occur in practice is what matters for the SEL approach, not the theoretical mean. Rather than guessing at the mean, I should adapt the simulator to handle the new modular scheme and get exact counts for a real candidate N. I'm also considering whether to expand beyond mod 225 to include additional moduli like 7, 11, and 13 in the column-skipping logic, though I need to think through the period calculations more carefully. I'm settling on the SEL-mod-675/225 scheme and need to define the core data structure: a giant literal blob that encodes, for each residue class modulo 225, the allowed exponents as sorted 10-bit slots, padded with 1023 when needed. The maximum class size is 425, which would require 9 bits to represent 512 capacity , creating some padding overhead for rare large classes, but the guard check after selection is cheap enough at around 8 operations. | | | | However, the padding becomes a real problem: for a typical pair with ~100 elements, padding to 512 slots means 412 cheap leaf operations at 40 microseconds each, totaling nearly 100 milliseconds—completely dominating the runtime. The fix is to store a variable field length per class 4 bits in the blob , so each pair's tree uses only the necessary capacity for that specific class size. With this approach, a class of 100 elements needs field length 7 128 capacity , giving just 28 padding leaves at 6.7 milliseconds, which is acceptable compared to the 84 milliseconds of useful work. | | | | Now I'm checking whether the allBH function properly takes the field length as an argument—it does, so the tree size scales correctly with 2^fL a. The overshoot from rounding up to the nearest power of two when K isn't a power of 2 creates extra leaves that the guard condition catches early, costing about 7% overhead, which is tolerable. I'm considering whether to keep K variable across different classes or fix it, and the exact-K approach with allB seems cleaner than trying to handle variable K with complex decode logic. | | | | For the metadata, I don't actually need to store the full L a values—the SEL function returns 1023 for padding slots, which the guard catches, so I only need the field length fL a as a 4-bit value per class. That's 225 classes × 4 bits = 900 bits total, packed into FLBLOB. Now I'm working out the per-pair leaf structure where I extract the field length from FLBLOB using the class index derived from the pair's address. | | | | For the selector blob itself, I'm deciding between variable offsets per class which requires storing an offset table or fixed-width slots per class. The fixed approach is simpler: allocate 512 slots × 10 bits per class, giving 5120 bits per class. That's 225 classes × 5120 bits ≈ 1.15 Mbit, which is about 144 KB—totally acceptable for the file size budget. I'm extracting the selector block for a given class by shifting and masking the appropriate 5120-bit chunk from SELBLOB. Checking that K stays within bounds for the coverage constraint, then implementing the leaf node function that extracts the block index and position within that block using bit operations. I'm working through the completeness argument for the decision procedure, establishing that when the square bit test fails for a given residue pair, no witness exists modulo 225. This requires a global lemma covering all cases within the 225×675 space, where I need to verify that the membership check and square bit computation are consistent across the entire lookup table. | | | | Now I'm reconsidering whether I actually need the explicit table at all—I could define membership directly through the square bit condition itself, which would eliminate the separate TBL structure and let me prove the linking property between the index function and selector in a single decision lemma without the intermediate lookup table. I need to establish the periodicity lemma rigorously by showing that p4 x+675 − p4 x is divisible by 5400, which would then give me c4 x+675 ≡ c4 x mod 225 after dividing by 24. Expanding the polynomial differences term by term for each degree, I get that the leading coefficient difference is 2700x³, which isn't divisible by 5400. But I've verified numerically that the period-675 constraint requires divisibility by 225, so I need to reconsider what divisibility condition actually applies here. I'm factoring out 2700 from the difference polynomial and checking divisibility of the coefficients — the x³ coefficient works out to 1017 when divided by 2700, but the constant term gives a non-integer result, so I need to reconsider whether the entire difference can be expressed as 2700 times a polynomial with integer coefficients. Rather than computing h x directly as a polynomial with integer coefficients, I'll use the standard approach of working with binomial basis or case analysis on parity. In Lean, the strategy is cleaner: prove that c4 x+675 and c4 x are congruent modulo 225 by showing p4 x+675 = p4 x + 2700·Q x as a ring identity over ℕ with Q having natural coefficients, then use the fact that 24 divides p4 x since it's a product of four consecutive integers, which connects to the binomial coefficient C x+3,4 via the identity p4 x = 24·C x+3,4 . | | | | I can leverage Nat.descFactorial to express p4 x = x+3 .descFactorial 4, which unfolds to the product x+3 · x+2 · x+1 ·x, and use the lemma relating descending factorials to binomial coefficients to establish the divisibility cleanly. | | | | Now for the recurrence relation: c4 x+675 = c4 x + 225·Q x /2, where Q x is a cubic polynomial. Since gcd 2700, 24 = 12, I need to show 2 divides Q x via a parity argument, then handle the modular arithmetic carefully—specifically that 2 is invertible mod 225, so the congruence c4 x+675 ≡ c4 x mod 225 follows from the divisibility. Qx/2 where Qx is even. I need to prove that Qx = x³ + 1017x² + 458668x + C is always even, which I can do by cases on whether x is even or odd—if x is even then x³ and x² are both even, and if x is odd then x + 1017 is even so x² x + 1017 is even. After substituting and simplifying with ring normalization, the divisibility by 2 becomes clear, though I'll need to handle the nonlinear terms carefully. | | | | I'm considering whether to prove periodicity modulo 225 by deciding over one period and using induction, or switching to a larger period like 5400 where the coefficient-wise divisibility might hold more cleanly across the polynomial. Verifying the fourth coefficient works out to give the complete polynomial identity with P = 2700, establishing that the shift formula holds as a pure ring identity over the natural numbers. | | | | Now I'm working through the division properties — since 24 divides p4 x , the formula for c4 x+2700 simplifies cleanly to p4 x + 5400·R x /24 = p4 x /24 + 225·R x , which I can verify using natural number division lemmas. | | | | The column period extends to 2700 instead of 675, which quadruples the completeness lemma cases to around 607,000 manageable in about 60 seconds , but the SELBLOB structure grows accordingly — with mean class size around 529 and capacity potentially up to 2048, the total blob size becomes 225·2048·12 bits. | | | | That translates to roughly 5.5 megabits or 690 kilobytes in binary, expanding to about 1.7 megabytes as a decimal file, which is substantial but potentially workable. I'm also considering whether a smaller period like 1350 could satisfy the divisibility constraints — checking if 5400 divides 4P and whether the polynomial coefficients divide evenly, but 1350 fails the second condition while 2700 appears to be minimal for this form. | | | | Now I'm exploring a hybrid approach using separate modular masks for mod 9 and mod 25 with their respective periods of 27 and 25, where I'd skip values that don't fall into the quadratic residue sets for either modulus. The density works out to 4/9 for the mod 9 mask, but when I check the coefficient divisibility for period 27, I run into issues — 216 doesn't divide 108, so I'd need P=54 instead, yet that still doesn't yield integer coefficients when I work through the polynomial arithmetic. | | | | Switching to period 108 for mod 9 works cleanly across all four polynomial coefficients, each dividing evenly by 216. For mod 25 with period 25, I need 600 to divide the coefficients, and P=300 gives me the divisibility I need, though I'm still verifying the higher-order terms work out. Now I'm checking the blob size constraints: with 225 classes and variable-width slots scaled by a factor of 4, the mean L a is around 529 and max reaches 1700, which translates to roughly 160K total slots at 12 bits each—about 241KB in binary or 580KB as a decimal literal. I need variable offsets to track where each class block starts in the blob, which requires 225 offset pointers at 21 bits each, and that's manageable. The extraction logic uses bit-shifting and masking to pull out the class block from the blob. | | | | For performance, a single shift-right operation on the 1.9Mbit literal per pair would involve a memcopy of around 240KB, taking maybe 30-100 microseconds per pair. With 55K pairs total, that's roughly 1.7 to 5.5 seconds—negligible overhead. But now I'm questioning whether I even need the parity and ring-identity lemma at all; maybe I can state the completeness result directly over the range 0, 2700 without that extra machinery. | | | | Actually, the key insight is that for any x = 2700k + e, the value v x mod 225 depends only on c4 e mod 225 due to periodicity. I'm setting up a Lean proof that establishes c4 has period 2700 modulo 225 by induction on k, then proving the step case shows c4 x + 2700 equals c4 x plus a multiple of 225. | | | | Now I'm working through the relationship between the polynomial p4 and the binomial coefficient c4, using the fact that c4 x = C x+3, 4 and connecting this to the descending factorial formula to establish divisibility. Perfect— Nat.factorial dvd descFactorial gives me exactly what I need: since 4 divides x+3 .descFactorial 4, and that's precisely p4 x, I have 24 ∣ p4 x. Then the divisibility carries through the modular arithmetic cleanly, so c4 x+2700 simplifies to c4 x + 225R using cancellation lemmas. | | | | Now I'm setting up the decidability check by partitioning the search space: for any x, I write it as x = a·2700 + e where a is the quotient and e is the remainder, then define a boolean predicate over all 607500 possible index pairs that checks whether the tree condition holds at each a, e combination using nested iteration over the ranges. | | | | The core check computes d from the column offset calculation handling the modular arithmetic carefully to avoid underflow , then branches on whether a bit flag K1bit g is zero—if so it's a fast path, otherwise it falls back to an index blob lookup that extracts the relevant bits and verifies the membership condition. | | | | Now I'm hitting the performance bottleneck: the index blob is massive over 800KB of bit-packed data , and each lookup requires shifting through millions of bits, which takes around 100 microseconds per query. With 120,000 lookups needed, that balloons to tens of seconds just for the membership checks, plus the decimal literal for the blob itself adds another 2MB to the file size. The whole proof kernel is creeping toward 3-4 minutes, which is borderline acceptable but getting unwieldy. I'm exploring whether I can trim the index to only store entries for valid a, e pairs, but that would require a rank function to map back to positions—too complex. A linear search through the class list would be even slower. Binary search over sorted data could work but adds significant definitional complexity. | | | | The better path is to use binary search directly on the sorted class list without the blob at all. I'd define a fuel-based recursive natural number search over the 12-bit sorted entries in the class buffer, with roughly 10 iterations at 6 operations each. That's about 60 operations per allowed pair, so 120,000 lookups × 60 ops × 5 microseconds gives me around 36 seconds—acceptable and no massive blob overhead. The binary search definition and its use in the decide tactic don't need a full soundness proof; the decide lemma itself verifies correctness by checking whether the search actually finds the element. The tricky part is making sure the decide lemma concludes something I can use downstream: it needs to return whether the binary search found the entry, and then in the soundness proof I can extract the existence witness from the LINK lemma. | | | | But actually, if the binary search returns true, I need to prove that some probed slot actually matched—that's provable by induction on the fuel since the search only returns true when a probe succeeded. Alternatively, since the allowed e-lists are contiguous and sorted within each class, I could just store a companion rank blob that counts how many allowed entries less than e exist in each class—that's the same 607,500 × 11 bits as the index blob, so it's really the same thing. Let me flip the completeness direction instead. | | | | Rather than proving "selected columns are in the SEL list," I could prove "non-selected columns are free of the constraint" by checking all columns outside the list—that's equivalent but requires quantifying over the complement. The cleanest approach is to embed the table masks directly in the x-tree and drop SEL entirely: for each pair, extract the class mask 2700 bits by shifting and masking the table blob, which is only 76KB total—quite manageable. Then build a hybrid tree over the 2700 possible e values. | | | | At each node level, I skip subtrees when the mask slice is zero, using a recursive tree definition that checks the mask range. For individual columns where the bit is set, I run the full k-loop checks. The soundness argument is direct: if bit e of the class mask is 0, then the constraint bit for that column must be 0, with no need for SEL, index lookups, or binary search. This gives roughly 45 seconds for 607,500 cases at ~15 operations each. | | | | Now I'm estimating the tree overhead by counting visited nodes across levels. With random density around 19.6% of set bits and 2,700 columns, I'm calculating how many nodes get visited by summing across subtree sizes, accounting for the probability that each subtree contains at least one set bit. At the smallest level with single columns, that's roughly 529 nodes out of 2,700. | | | | Continuing through larger subtree sizes—pairs, quads, octets, and so on—the total node-tests come to around 1,480, where each test involves 3-4 GMP operations on numbers up to 2,700 bits, taking about 30-40 microseconds including structural overhead. That multiplies out to roughly 52 milliseconds per pair, which is problematic since it's comparable to the actual useful computation time. At lower density around 8%, the numbers drop significantly but the pattern remains concerning. | | | | With a period of 2,700 and maximum value around 3,500, the K-factor is 2, so the useful leaves span 432 to 1,060 nodes at 140 microseconds each—60 to 148 milliseconds of actual work. The mask-tree overhead sits at 36 to 52 milliseconds, adding roughly 30% on top. That brings the total per pair to around 96 milliseconds, which would be a 4.7× improvement over the current 450 milliseconds, though it's worth comparing against a simpler SEL approach that avoids per-column tree overhead entirely. So K=2 handles all values up to 3.5e13 without needing a K-tree or Newton iteration. For the leaf level, I'm checking that when j is shifted right by fLa, it gives either 0 or 1, which maps to the tree at fLa+1. The pair-level verification is straightforward—I just need to confirm that W stays within bounds and that c4 5400 exceeds W globally, which holds since W ≤ N < 3.5e13. | | | | For the implementation, I'm precomputing c4 5400 as a constant rather than recalculating it each pair, keeping the kernel lean. With padding overhead from doubling up to the next power of 2, the cost is roughly 8 operations per leaf, translating to about 40 microseconds. Given the actual density from simulation around 8.3%, the mean leaf count comes out to roughly 224, so the padding overhead stays manageable at around 15% of the total cost. | | | | Now I'm working through the per-pair timing: useful leaves at 224 per pair take about 63 milliseconds, padding adds roughly 2.6 milliseconds, and pair-level overhead is negligible, giving about 66 milliseconds per pair versus 450 milliseconds baseline—a 6.8× speedup. Scaling to N=5.5×10¹² pairs yields around 3660 seconds, which aligns with the earlier 6.8-hour estimate of 24500 seconds divided by 6.8. At N=1.3×10¹³, that stretches to about 95 minutes single-threaded, though async elaboration could push it down to 6–10 minutes. The 140-microsecond useful-leaf cost is an estimate, so there's room to optimize further, possibly by skipping K1 in certain cases. | | | | For the next steps, I need to check whether avoiding high-cost classes those with L a up to 1700, which would cost 480 milliseconds per pair is likely given the class distribution at our target N, then verify the parallelism results from pt8 and double-check the scan99 behavior. | | | | After that, I'll modify the simulator to use the v5 scheme with precomputed blobs to get exact counts and validate against v4 on a known test case like N=23343989. Then I'll write out the Lean v5 definitions and soundness proofs in Dev/Checker.lean, compile and test them, and benchmark the per-leaf cost on a realistic fake W with estimated density. | | | | But I'm realizing there's a subtlety with the SEL soundness formulation — I still need the membership machinery either bsearch or IDX blob to verify that when sqbit returns 1, the element is actually in the slots. Let me clarify: the soundness statement is that for all a and e, if sqbit g a,e =1 then e must be in the slots, and I'll need the bsearch-in-decide lemma plus bsFind-soundness to establish this. | | | | Now I'm looking at the bsFind implementation — it's fuel-based, probing the midpoint in a binary search over the range lo, hi and returning true iff the element is found. The soundness proof found implies the element exists at some index less than 2^fLa follows by induction and is moderate complexity. I'm also considering whether a simpler linear scan with early exit would work, but with L around 1700 and 607K queries that's prohibitive. Another option is an exists-tree using an OR-tree over all indices, but querying that for 120K entries would cost around 300 seconds, which is too slow. Binary search looks like the right balance. | | | | Comparing this to the IDX-blob approach: that avoids needing a search definition and soundness lemma since it's just a direct lookup and slot check, but it adds 835KB of extra data and has a big-shift cost. I can optimize the big-shift by using a two-level lookup structure where for each outer class, I extract the class-specific index and content blobs once, then reuse them across all inner queries on different elements. The mask-building approach via fold creates a performance bottleneck if called repeatedly per kernel, so I should avoid that pattern. Instead, I'm considering a simpler strategy: exploit the sortedness property through monotone-cover completeness, where the decide lemma verifies for each class that slots are strictly increasing up to a sentinel, then checks additional constraints. | | | | But this still requires iterating through elements per class, which brings back the chain-state inefficiency. Binary search adds minimal overhead with just a generic definition and one soundness proof, making it cleaner than trying to encode completeness through complement-run patterns or per-pair constraints that would explode the proof size. I'm leaning toward the bsearch approach as the most straightforward implementation. At 8-20% density, the per-column test approach becomes more practical—I'd just test each bit directly at the leaf level rather than building a tree structure. The cost per pair would be dominated by testing all 2700 columns roughly 35 microseconds per skipped column plus the shift overhead for the 2700-bit mask, which is manageable. | | | | But comparing this to SEL, which only touches allowed columns and offloads completeness to a global lemma, SEL is fundamentally more efficient—it avoids the overhead of testing skipped columns entirely. So I'm going with SEL plus binary search for completeness, rather than trying to optimize the skip-test approach further. | | | | For the completeness check, I'm nesting an outer loop over the 225 classes to extract the column bitmap, then an inner loop over the 2700+ elements using a predicate that returns true for elements ≥ 2700 via a conditional on the bit-length comparison. The binary search function takes a fuel parameter for termination, a low and high bound defining the search range, and returns whether the element exists—it recurses by computing the midpoint, extracting the relevant bits from the column bitmap, and continuing the search based on the comparison. | | | | For soundness, the binary search is correct by induction on fuel: if it returns true, there exists an index where the extracted bits match the target element. The key insight is that no ordering assumption is needed for this proof. In the tree soundness argument, I need to verify that whenever an element exists in a slot, that slot index is covered by the tree enumeration—the tree spans all indices less than 2^fLa, and the column bitmap has exactly 2^fLa slots, so slots beyond that range are zero. | | | | The binary search itself only examines indices in 0, 2^fLa , which is guaranteed by the initial call bounds. I should strengthen the soundness statement to explicitly require that the found index satisfies lo ≤ i < hi, which the induction handles cleanly since mid always falls within the search range. Then the leaf-tree verification checks whether x matches 2700k plus the slot value, but I need to handle the case where x ≥ 5400 k ≥ 2 , which appears to be covered by an earlier case. | | | | For the non-square case, I'm using the period lemma to show that v mod 225 equals the bit value, and the mask soundness property which states that all quadratic residues mod 225 have their corresponding bits set gives a contradiction. When the bit is set, the completeness lemma confirms the binary search succeeds, yielding an index i < 2^fLa where slot i = e, and then the tree covers all j in 0, 2^ fLa+1 by decomposing j as k·2^fLa + i with k ∈ {0,1}. | | | | Now I need to verify the leaf decoding: extracting k' = j fLa and i' = j & 2^fLa - 1 recovers the original k and i, and the slot value e' = slot i = e reconstructs x' = 2700k + e = x, so the leaf passes the square test and contradicts the non-square property. I'm looking for the right Mathlib lemmas for bitwise operations—specifically that right-shift by fLa divides correctly and the bitwise AND with the mask extracts the lower bits. | | | | The completeness lemma needs to align with the same g a,e definition used in the soundness proof and the same fLa/CB extraction from the runtime tree, stating that whenever sqbit225 g a e = 1, the binary search returns true with the correct parameters. Working through the modular arithmetic proof for the derivation lemma, establishing that A8 − 8c4x % 225 ≡ a − d mod 225 where d = 8·c4 x % 225, then converting this to natural number subtraction using omega-friendly tactics. I can prove the subtraction modulo lemma directly with omega since it handles modular arithmetic with constant divisors, and the offset of 1800 = 8·225 ensures the subtraction stays well-defined. For the quadratic residue check, I'm leveraging the existing mask over 225 that marks all quadratic residues, so if a value isn't a quadratic residue mod 225, it can't be a perfect square. | | | | Now for the blob generation in Python, I'm iterating through each residue class and collecting all valid exponents that produce allowed values, then computing the tree depth needed to encode that list with a sentinel guard for out-of-range lookups. | | | | I need to verify the period-2700 polynomial identity numerically and check the R coefficients match the expected form, then confirm the fLa cap stays within 15 bits since the maximum list size is bounded by 2700. | | | | One more thing to clarify: when a = A8 % 225, the value is always in range 0,225 , and since A8 = 8W+1 is always odd, I should double-check whether a itself ends up odd or even depending on how the modulo reduction works. | | | | For the per-pair structure in leafY5, I'm computing b := r8 + c6·y, then checking if N ≤ b to decide the branch, and if true, setting W := N−b and A8 := 8W+1 before recursing into xtreeOK4. | | | | Now I'm defining the core verification function xtreeOK5, which takes W and computes A8 := 8W+1, reduces it modulo 225 to get a, looks up its factorization level fLa and the corresponding bit-blob CB, then checks that allBH covers all j values up to 2^ fLa+1 and that W stays below the precomputed bound C5400. | | | | Defining leafX5... Defining the soundness proof for leafX5... When the true case holds, I apply the COMP lemma with the bounds on a and e to get a bit array lookup, then use the soundness of the bit array and leaf decoding to extract an index i, construct j from k and i, and derive a contradiction by showing that t2w plus c4 applied to the reconstructed value doesn't equal W, which contradicts our assumption that x has this form. | | | | Now I need to make sure the expression for Bof a is defined consistently—it's computed inline in xtreeOK5 but should be extracted as a shared definition so both places use the same CBof. I'm also checking the c4 period lemma, which establishes that c4 is periodic modulo 225 by induction on the step relation, where adding 2700 to the input adds a specific polynomial multiple of 225 to the output. | | | | For the proof, I'm using the fact that 24 divides p4 y from the descending factorial divisibility theorem , so c4 y = p4 y / 24 is well-defined. Then I can verify the periodicity by showing that when x increases by 2700, the p4 value increases by exactly 24 times 225 times some polynomial, which means after dividing by 24 and taking modulo 225, the c4 values match. The key step is canceling the factor of 24 using natural number equality. | | | | Now I need to verify the actual numerical coefficients in the ring identity, confirm the parallelism result holds, and then implement this. I should also keep monitoring scan99b. | | Part 1 took 72 seconds wall time with only 17 seconds of user time due to heavy external contention. Now I'll check the 8-theorem parallelism test and verify the period-2700 ring identity for c4. | | bash | | | | cat /tmp/pt8.log 2 /dev/null; echo ====; python3 - <<'EOF' | | import sympy as sp | | x=sp.symbols 'x' | | p4=x x+1 x+2 x+3 | | d=sp.expand p4.subs x,x+2700 -p4 | | print d | | q=sp.simplify d/5400 | | print sp.expand q | | print all c =0 and int c ==c for c in sp.Poly q,x .all coeffs | | EOF | | tail -2 /tmp/scan99b.err | | | | | | 128 --- TOOL bash --- | | | | real 7m3.393s | | user 2m18.006s | | sys 0m4.144s | | ==== | | 10800 x 3 + 43788600 x 2 + 78863279400 x + 53262278206200 | | 2 x 3 + 8109 x 2 + 14604311 x + 9863384853 | | True | | |S3|=348144743 2.79 GB | | block 1/35 done marks=165241602558 zeros=0 | | | | | | 129 --- ASSISTANT --- | | The ring identity check for the polynomial transformation is verified, and the parallelism test shows that user time scales linearly with the number of theorems 8 theorems taking roughly 8 times the user time of 1 theorem , but the wall clock time isn't improving proportionally, indicating the system isn't achieving true parallelism. | | | | I should test whether async elaboration can be enabled via the Elab.async flag in Lean 4.27, since it might default to false in the CLI but true in lake builds. The machine is only using about 30% of CPU capacity based on the user-to-wall-time ratio, which suggests contention or lack of parallelization. I also need to check the timing on the scan99b block progress to see where the bottleneck is. | | Ring identity verified with no parallelism detected, so I'll now test Elab.async explicitly and check the scan progress timing. | | bash | | | | cd /workspace/leanproject && nohup bash -c ' time lake env lean -DElab.async=true /tmp/partest.lean /tmp/pt8a.log 2 &1' & ls -l --time-style=full-iso /tmp/scan99b.err; date; grep -c . /tmp/scan99b.err | | | | | | 129 --- TOOL bash --- | | -rw-r--r--. 1 root root 68 2026-08-02 22:01:38.979383464 +0000 /tmp/scan99b.err | | Sun Aug 2 22:11:19 UTC 2026 | | 2 | | | | | | 130 --- ASSISTANT --- | | The scan block finished in about 9 minutes, leaving 34 blocks to process over roughly 5 hours to hit the target. While the next scan runs, I'm building out the Python simulator to version 5, creating the blob structures with the proper selection and offset logic, implementing the exact leaf and tree semantics including the completeness validation, then verifying the master result matches. | | | | I'm also checking that the counting model with per-operation cost weights estimates kernel time accurately, validating that for every bit position marked in the selection array the blob finder locates the corresponding entry, and simulating exact leaf counts for candidate N values around 5.5e12 to distinguish useful leaves from padding. The blob layout needs to match the Lean definitions precisely: the frequency lookup block stores log-scaled slot counts per position, the offset block holds bit positions into the selection blob using 24 bits per entry, and the selection blob itself concatenates the actual slot values in little-endian format with 4095 as a sentinel for padding. | | | | Defining the Lean functions... Defining the search function... Working through the induction on the fuel parameter—when fuel is zero it's a contradiction, and in the successor case I need to handle the three branches: when the bounds are invalid, when the element matches, and when I need to recurse on either the upper or lower half. The bounds weakening follows naturally from the recursive calls. I also need to establish that the bit shift operation correctly implements division by powers of two for the decoding lemmas. | | | | Now I'm defining a verification function that constructs a specific tree configuration by computing parameters from a given width value, then checking that all elements in the resulting tree satisfy the bounds property and that the width itself stays within acceptable limits. Computing the division and subtraction for the candidate value, then running the quadratic residue test with modulo 539 to filter out most non-squares early—the combined operation count across the guard checks and residue test comes to roughly 26 structural operations plus tree overhead, estimating around 33 total steps or 150 microseconds per leaf, with padding leaves taking about 45 microseconds. | | | | I could optimize by precomputing the mask as an argument passed through the leaf function to save a couple operations per leaf, bringing it down to about 31 steps, though I'd need to compute that mask once at the pair level. The guard ordering is constrained by data dependencies, but I could explore different packing strategies using 12-bit slots with shifted multiplication to reduce overhead further. | | | | Looking at the performance breakdown: useful leaf work comes to about 65ms, padding overhead around 3ms, internal tree nodes contribute roughly 6ms, and pair-level operations with the big shift operations add another quarter millisecond. That puts me at roughly 74ms per pair, and with 55,000 pairs to process, I'm looking at around 68 minutes of kernel and user time at the target throughput. Wall-clock time could stretch to three times that on this machine due to contention, though the verifier's hardware is unknown—but this seems acceptable, so I'll move forward. | | | | Now I'm considering whether I can optimize further by adjusting the column mask strategy. Currently using modulus 225, but I'm exploring whether I could combine it with another modulus that divides evenly into 2700. Modulus 25 already works, and I'm checking if 27 fits—but 2700 divided by 81 doesn't give a whole number, so that's out. Similar issues with 49, 11, and 7 as divisors of 2700, which only factors as 2² × 3³ × 5². The modulus 225 is the sweet spot for this period analysis. For a fixed exponent, the value mod 225 stays the same across different k values, but other moduli give different results—no easy optimization there. I'm estimating the total runtime at 65-75 minutes for a single-threaded kernel at N around 5.5e12, though the actual candidate N will likely be larger 8e12 to 2e13 , which could push it to around 2.3 hours at the high end with some contention overhead, but that's still acceptable. Let me check the pt8a result and then write the simulation code. | | I'm writing the v5 simulator with blob generation and checking the async test result. | | bash | | | | cat /tmp/pt8a.log 2 /dev/null; cat /tmp/sim5.py <<'EOF' | | v5: SEL-blob mod-225/period-2700 scheme; exact Lean semantics simulation + blob generation | | from math import comb | | import sys, pickle | | from sim import K1,K2,K3,K4,R1,R2,R3,R4, c4,c6,c8, log2n, newton, St | | | | ---- blob generation ---- | | def sqbit m : return K1 m &1 m in 0,225 | | def g225 a,e : return a+1800 - 8 c4 e %225 % 225 | | | | def build : | | FLB=0; OFFB=0; SELB=0; off=0 | | meta= | | for a in range 225 : | | allowed= e for e in range 2700 if sqbit g225 a,e ==1 | | L=len allowed | | f=0 | | while 1<<f <max L,1 : f+=1 | | S=1<<f | | slots=allowed+ 4095 S-L | | assert off < 1<<24 | | OFFB |= off << 24 a | | FLB |= f << 4 a | | for i,s in enumerate slots : SELB |= s << off+12 i | | meta.append L,f,off | | off += 12 S | | return FLB,OFFB,SELB,meta,off | | | | FLB,OFFB,SELB,META,TOTBITS = build | | | | def fla a : return FLB 4 a &15 | | def cbof a : | | o= OFFB 24 a &16777215 | | return SELB o & 1<< 12 1<<fla a -1 | | | | def bsA CB,e,fuel,lo,hi : | | while fuel 0: | | if hi<=lo: return False | | mid= lo+hi //2 | | s= CB 12 mid &4095 | | if s==e: return True | | if s<e: lo=mid+1 | | else: hi=mid | | fuel-=1 | | return False | | | | def comp check : | | bad= | | for a in range 225 : | | f=fla a ; CB=cbof a | | for e in range 2700 : | | if sqbit g225 a,e ==1: | | if not bsA CB,e,f+1,0,1<<f : bad.append a,e | | return bad | | | | ---- runtime v5 ---- | | from sim import S | | S.pad=0; S.useful=0 | | def sqTest2v v : | | S.sq2+=1 | | if K2 v%R2 &1==0: return True | | if K3 v%R3 &1==0: return True | | if K4 v%R4 &1==0: return True | | from sim import bracketOK | | return bracketOK v | | | | def leafX5 A8,CB,f,msk,j : | | S.xleaf+=1 | | i=j&msk | | e= CB 12 i &4095 | | if 2700<=e: S.pad+=1; return True | | S.useful+=1 | | k=j f | | x=2700 k+e | | t=x x+3 ; c=t t+2 //24 | | v=A8-8 c | | if v<0: v=0 | | if v<=1: return True | | return sqTest2v v | | | | def xtreeOK5 W : | | S.pairs+=1 | | A8=8 W+1; a=A8%225; f=fla a ; CB=cbof a ; msk= 1<<f -1 | | if not W < c4 5400 : return False | | for j in range 1<< f+1 : | | if not leafX5 A8,CB,f,msk,j : return False | | return True | | | | def leafY5 N,r8,y : | | b=r8+c6 y | | if N<=b: return True | | return xtreeOK5 N-b | | | | def ytreeOK5 N,fy,r8 : | | if not N<=r8+c6 2 fy : return False | | for y in range 2 fy : | | if not leafY5 N,r8,y : return False | | return True | | | | def leafZ5 N,fy,z : | | r8=c8 z | | if N<=r8: return True | | return ytreeOK5 N,fy,r8 | | | | def master5 N,fy,fz : | | if not N<=c8 2 fz : return False | | for z in range 2 fz : | | if not leafZ5 N,fy,z : return False | | return True | | | | if name ==" main ": | | if sys.argv 1 =="build": | | bad=comp check | | print "comp bad:",len bad | | Ls= m 0 for m in META | | print "TOTBITS",TOTBITS, "bytes",TOTBITS//8, "meanL",sum Ls /225,"maxL",max Ls ,"minL",min Ls | | pickle.dump FLB,OFFB,SELB ,open "/tmp/blobs.pkl","wb" | | else: | | N=int sys.argv 1 ; fy=int sys.argv 2 if len sys.argv 2 else 9; fz=int sys.argv 3 if len sys.argv 3 else 8 | | ok=master5 N,fy,fz | | print "N",N,"result",ok | | print "pairs",S.pairs,"xleaf",S.xleaf,"useful",S.useful,"pad",S.pad,"sq2",S.sq2,"bracket",S.brk | | EOF | | cd /tmp && python3 sim5.py build | | | | | | 130 --- TOOL bash --- | | comp bad: 0 | | TOTBITS 2052528 bytes 256566 meanL 528.0 maxL 1700 minL 0 | | | | | | 131 --- ASSISTANT --- | | The blob construction completed successfully with a 2.05Mbit binary file, and the compression check passed with a mean length of 528 and max of 1700. I need to check on pt8a.log since it appears empty, then run the v5 runtime against v4 on the large test case N=23343989 to verify the expected failure, plus test a few covered values to compare the counts. | | bash | | | | cd /tmp && python3 sim5.py 23343989; echo ---; python3 - <<'EOF' | | leaf-count estimator for v5 no inner loop over j; per pair count = 2^ f+1 | | from sim5 import fla, cbof, META | | from sim import c4,c6,c8 | | def count N,fy=9,fz=8 : | | tot=0; useful=0; pairs=0 | | for z in range 2 fz : | | r8=c8 z | | if N<=r8: continue | | for y in range 2 fy : | | b=r8+c6 y | | if N<=b: continue | | W=N-b | | a= 8 W+1 %225; L,f,off=META a | | pairs+=1; tot+=2 f+1 ; useful+=2 L | | return pairs,tot,useful | | for N in 5527622910038, 8000000000000, 13000000000000, 20000000000000 : | | p,t,u=count N | | print N,"pairs",p,"jleaves",t,"useful",u,"est min @150us useful+45us pad: %.1f"% u 150e-6+ t-u 45e-6 /60 | | EOF | | cat /tmp/pt8a.log 2 /dev/null; tail -1 /tmp/scan99b.err | | | | | | 131 --- TOOL bash --- | | N 23343989 result False | | pairs 1331 xleaf 1404754 useful 974706 pad 430048 sq2 25636 bracket 249 | | --- | | 5527622910038 pairs 55492 jleaves 58291554 useful 40881120 est min @150us useful+45us pad: 115.3 | | 8000000000000 pairs 61877 jleaves 85649008 useful 57829944 est min @150us useful+45us pad: 165.4 | | 13000000000000 pairs 71509 jleaves 133740782 useful 90538544 est min @150us useful+45us pad: 258.7 | | 20000000000000 pairs 81157 jleaves 113595136 useful 75550592 est min @150us useful+45us pad: 217.4 | | block 1/35 done marks=165241602558 zeros=0 | | | | | | 132 --- ASSISTANT --- | | I'm noticing the useful-per-pair ratio is much higher than expected at around 737, which would suggest a mean sequence length of about 368—but that's lower than the earlier uniform estimate of 528 for period 2700, so there's some inconsistency in how the class counts are biased. I need to account for how the sq2 count will be smaller when recalculating for N=23343989. | | | | Now I'm seeing that v5's approach with xleaf at 1.4M is actually performing worse than v4's 308K at small N, because v5 enumerates the full period 2700 regardless of xmax, leading to massive overkill when pairs have small W values—those excess x values exit quickly but still incur overhead from computing t, c, v operations. At N=5.5e12, most pairs have xmax around 3400, but many pairs have W much smaller than N, and for those with W below the 2700-equivalent threshold roughly 2.22e12 , the k=1 case becomes useless since b exceeds 3.3e12, which represents a significant fraction of the total pairs. | | | | The solution is to add per-pair limits on k and e: either use a k-limit that switches between k ∈ {1,2} and k ∈ {0} based on whether c4 2700 fits within W, or add an e-limit within k=0 for small W cases to avoid enumerating slots that won't contribute. I'm working through the leaf-level exit strategy: computing the encoded value and comparing it against a precomputed capacity threshold to decide early termination. The key insight is that by passing a pair-level xcap value down to each leaf, I can do a cheap comparison to determine if the leaf will exceed the work budget W, avoiding expensive fourth-root calculations. The soundness argument hinges on proving that if the comparison succeeds, then the fourth power of any value beyond xcap definitely exceeds W — which requires verifying the pair-level check holds. Now I'm refining the tree structure by introducing an fx-limit that adjusts based on whether W exceeds the threshold, which reduces wasted computation from leaves that exit early at the xcap boundary. The per-pair cost model with these constraints gives me a concrete estimate of how many full leaves actually contribute useful work versus how many are discarded. Now I'm refining the estimator to compute xmax based on W, then determining how many slots fall within that threshold versus the cheaper exit path. The cost calculation combines the full-path overhead at around 150 microseconds per pair with the cheaper sentinel-pad route at 40 microseconds, plus the node traversal cost scaled by the leaf count. I'm noticing from the v4 comparison at N=23M that v5 performed worse in certain cases, likely tied to handling small W pairs, but the xcap-exit and fx-limit adjustments should resolve that. | | I've identified that v5 needs a per-pair xcap early-exit optimization since slots are sorted but cover the full period even with small xmax values. Now I'll model that refinement. | | bash | | | | cd /tmp && python3 - <<'EOF' | | from sim5 import META, fla, cbof | | from sim import c4,c6,c8 | | import bisect | | per class: sorted real slot list | | SL= | | for a in range 225 : | | L,f,off=META a | | CB=cbof a | | SL.append CB 12 i &4095 for i in range L | | C2700=c4 2700 | | def isqrt n : | | import math; r=int math.isqrt n ; return r | | def count N,fy=9,fz=8 : | | full=0; cheap=0; pairs=0; leaves=0 | | for z in range 2 fz : | | r8=c8 z | | if N<=r8: continue | | for y in range 2 fy : | | b=r8+c6 y | | if N<=b: continue | | W=N-b | | a= 8 W+1 %225; L,f,off=META a ; sl=SL a | | xcap=isqrt isqrt 24 W | | assert W < c4 xcap+1 | | fx = f+1 if W = C2700 else f | | assert W < c4 2700 1<< fx-f +0 or True | | nfull=0 | | for k in range 1<< fx-f : | | lim=xcap-2700 k | | if lim =0: nfull+=bisect.bisect right sl,lim | | pairs+=1; leaves+=1<<fx; full+=nfull; cheap+= 1<<fx -nfull | | return pairs,leaves,full,cheap | | for N in 5527622910038, 13000000000000, 20000000000000 : | | p,l,f,c=count N | | est= f 150e-6+c 42e-6+l 10e-6 /60 | | print N,"pairs",p,"leaves",l,"full",f,"cheap",c,"est %.0f min"%est | | EOF | | | | | | 132 --- TOOL bash --- | | 5527622910038 pairs 55492 leaves 54100871 full 23562410 cheap 30538461 est 89 min | | 13000000000000 pairs 71509 leaves 130141404 full 64601679 cheap 65539725 est 229 min | | 20000000000000 pairs 81157 leaves 111855840 full 60107953 cheap 51747887 est 205 min | | | | | | 133 --- ASSISTANT --- | | I'm working through the density calculations for the full and cheap cases, checking whether the 23.5M entries at that scale actually match the expected 8.3% density or if it's running higher at around 12.5%. | | | | The cheap case is bloated at 30.5M because the rounding up of L to the next power of two creates a lot of wasted padding slots, especially in the k=1 tree where most slots exceed the capacity threshold. I'm considering splitting the tree structure into separate k=0 and k=1 variants with different index ranges, where the k=1 tree only covers the slots that actually fall within the useful range. This would require computing a tighter bound f1 at the pair level using binary search to count how many slots stay below the capacity limit, then only allocating tree space for those—the rest would be guaranteed to exceed capacity by sortedness. | | | | Alternatively, I could just optimize the cheap-leaf operation itself, which currently costs around 9-10 operations. Reordering the checks to exit early on the e condition might shave off some cycles. | | | | Another angle is shrinking the slot lists by exploiting the structure of valid N-classes — if N must satisfy certain modular constraints, maybe I can prune candidates more aggressively. The residue coverage looked promising at first, but the earlier 8.3% variance at N=23M suggests that approach might not generalize well. | | | | I'm also considering a two-level masking strategy to further reduce the search space. I'm exploring whether I can compute c₄ directly from slot values using a ring identity, but the arithmetic overhead makes it no cheaper than the current approach. Now I'm considering a second filtering layer using modulus 539 to prefilter candidates by k₂-mask, though the period doesn't divide evenly into 2700. | | | | I'm also weighing several other optimizations: using sentinel values to speed up boundary checks, reducing the pair count or y-range though both are mathematically fixed , splitting the proof into separate files risky since the verifier's timeout is unknown , or leveraging parallelism through Lean's async elaboration. | | | | For the most promising angle, I'm exploring batching adjacent slots in the tree to share computation—decoding the key once and extracting two exponent values from a single shift operation would save a few operations per slot and roughly halve the tree nodes needed. | | | | Now I'm investigating whether choosing a mask modulus like 1125 which factors as 9·125 could reveal useful periodicity patterns. Looking at binomial coefficients modulo powers of 5, the period seems to scale with the prime power itself—mod 5 gives period 5, mod 25 gives period 25, so mod 125 might give period 125, though the pattern with mod 9 jumped from 3² to 3³ which complicates things. | | | | The key insight is that for p=5, since 4 < 5, Lucas' theorem keeps things digit-local, so the period should match the modulus. I'm now trying to estimate the density of quadratic residues modulo 125 and 1125 to see if this helps with the leaf-equivalent problem. The period works out to 6750 slots per equivalence class, giving around 1080 full leaves with 2048 leaves per pair, but this creates inefficiency since the maximum value caps out much lower than the slot capacity, leaving many slots unused beyond the practical range. | | | | Comparing the density: mod-225 achieves 425 full leaves while mod-1125 only gets 347 due to lower density, making the cheap leaves worse 1700 vs 550 , so this approach isn't worth pursuing. | | | | Instead, I'm exploring a better tree structure that uses exact leaf counts without rounding up to powers of two, relying on guard checks to handle boundary cases—the real bottleneck is the full leaves at 59 minutes, not the cheap padding which only adds 21 minutes. | | | | The key next step is actually measuring the full-leaf cost in the Lean kernel rather than guessing at 150μs from operation counts; it might be significantly better if the operations inline efficiently, so I need to benchmark a realistic scenario with the tree on a large number before finalizing the definitions. Writing Lean implementation... if W is large enough to require k=1, I set fx = f+1 valid up to the constraint that W < c4 5400 , otherwise fx = f. Then I'm computing xcap using nested square root operations via Newton's method on 24W, which converges reliably to the floor of the iterated square root even for large values like 2^47. | | | | The key insight is that if m = ⌊ 24W ^{1/4}⌋, then c4 m+1 is always greater than W, which guarantees the sentinel condition holds at runtime. Now I'm refactoring the leaf computation to extract the exponent field from the packed data and check against the 2700 threshold. Writing the verification function... I'm verifying the bounds on k and the parity bit e, then working through the two cases for the color-free check. When it's true, the parity constraint rules out a perfect square. When it's false, I use the compression algorithm to find a slot containing e, construct the tree index j, and verify the decoding recovers the original values correctly. Verifying the modular arithmetic for g225 by confirming that the multiplication and modulo operations commute correctly, then setting up the omega-friendly equality with substitutions a and d to complete the proof. I'm realizing that recomputing cbof for each e value is inefficient since it involves a massive bit shift operation on a 2-megabit structure, making the overall computation prohibitively slow. I need to restructure the function to extract cbof once upfront and reuse it across all iterations, along with precomputing the flag value. | | | | Now I'm noticing a potential issue with the guard condition—when a is in the range 225, 256 , the flag value becomes 0, which could cause compA to behave unexpectedly or return false. I should add a guard to ensure compA only runs for valid values of a , specifically checking that a ≥ 225 before executing the main logic. | | | | Analyzing the per-element cost... I'm reconsidering the binary search cost: each iteration involves a handful of operations like comparisons, shifts, and arithmetic, which comes to around 650 microseconds across the 10-11 iterations needed, totaling roughly 77 seconds for all 118K cases—still within acceptable bounds. Also realizing that sortedness isn't actually required anywhere in this approach. | | | | For the soundness and completeness checks, the binary search algorithm doesn't need the input to be sorted; completeness is verified by the decide tactic, which will simply fail if the blob is incorrect. The master5 version mirrors v4 but uses an updated tree structure in the leaf case. | | | | Now I'm laying out the implementation steps in the Lean checker file: establishing the relationship between p4 and c4 through divisibility, deriving a step function for c4 with a polynomial expression, proving periodicity modulo 225, handling modular arithmetic with a helper lemma, and defining the boundary and offset constants. | | | | Generating blob literals... | | I'll check the async test result, then start implementing v5 in Lean. | | bash | | | | cat /tmp/pt8a.log 2 /dev/null; echo ===; cd /workspace/leanproject && grep -rn "land two pow sub one\|and two pow sub one" .lake/packages/ /Mathlib/Data/Nat/ 2 /dev/null | head; rg -n "theorem. land. mod|land two pow" .lake/packages/mathlib/Mathlib/Data/Nat/Bitwise.lean | head | | | | | | 133 --- TOOL bash --- | | | | real 2m17.370s | | user 2m14.148s | | sys 0m2.645s | | === | | | | | | 134 --- ASSISTANT --- | | Looking at the timing data from pt8a with async enabled—wall time is 2m17s while user time is 2m14s, which is nearly identical. That's the same total work as pt8 user time around 134s matches pt8's 138s , but the wall time is dramatically shorter than pt8's 7m3s. This suggests the machine contention that was causing pt8's longer wall time has disappeared, but the fact that user equals wall indicates the async didn't actually achieve parallelism—it's still running on a single core. | | | | The kernel operations in decide +kernel might be protected by a mutex or executing in the same task, preventing the parallelization that Elab.async should theoretically enable. So no parallel speedup here—just single-threaded execution. Now I need to search more broadly for the land lemma since the grep didn't find anything. | | No async speedup available since user time matches wall time, so I'll stick with a single-threaded kernel. Now I need to find the land/mod lemma name. | | bash | | | | cd /workspace/leanproject && rg -n "2 \^ n - 1|two pow sub one|land. % 2|&&& \ 2" .lake/packages/mathlib/Mathlib/Data/Nat/Bitwise.lean .lake/packages/lean4? -S 2 /dev/null | head; rg -rn "theorem Nat.and two pow sub one eq mod|and pow two sub one|Nat.land eq" --glob " .lean" .lake/packages/mathlib/Mathlib/Data/Nat/ | head; rg -n "and two pow|land" $ dirname $ which lean /../lib/lean4/library/Init/Data/Nat/Bitwise/Lemmas.lean 2 /dev/null | head -20 | | | | | | 134 --- TOOL bash --- | | | | 135 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && cat /tmp/findlem.lean <<'EOF' | | import Mathlib | | open Nat in | | example j f : Nat : Nat.land j 2^f - 1 = j % 2^f := by | | exact? | | EOF | | timeout 240 lake env lean /tmp/findlem.lean 2 &1 | head -5 | | | | | | 135 --- TOOL bash --- | | /tmp/findlem.lean:4:2: error: exact? could not close the goal. Try apply? to see partial suggestions. | | | | | | 136 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && cat /tmp/findlem.lean <<'EOF' | | import Mathlib | | example j f : Nat : j &&& 2^f - 1 = j % 2^f := by exact? | | example j f : Nat : Nat.land j 2^f - 1 = j % 2^f := by simpa HAnd.hAnd, AndOp.and using Nat.and two pow sub one eq mod j f | | EOF | | timeout 240 lake env lean /tmp/findlem.lean 2 &1 | head -8 | | | | | | 136 --- TOOL bash --- | | Try this: | | apply exact Nat.and two pow sub one eq mod j f | | | | | | 137 --- ASSISTANT --- | | I found that Nat.and two pow sub one eq mod gives us the bitwise AND relationship we need, and the second example compiled successfully. Now I'm planning to generate the v5 Lean code by creating a Python script to produce the blob definitions for FLB, OFFB, and SELB into Dev/Blobs.lean, then set up Dev/Checker5.lean to import both Dev.Checker and Dev.Blobs. I should also verify the lakefile configuration for the Dev library. | | The lemma exists. Now let me generate the blob file and write the v5 Lean code. | | bash | | | | cd /workspace/leanproject && cat lakefile 2 /dev/null; ls Dev Submission | | | | | | 137 --- TOOL bash --- | | Copyright 2025 The Formal Conjectures Authors. | | Licensed under the Apache License, Version 2.0 the "License" ; | | you may not use this file except in compliance with the License. | | You may obtain a copy of the License at | | https://www.apache.org/licenses/LICENSE-2.0 | | Unless required by applicable law or agreed to in writing, software | | distributed under the License is distributed on an "AS IS" BASIS, | | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | | See the License for the specific language governing permissions and | | limitations under the License. | | | | name = "formal conjectures" | | keywords = "math" | | defaultTargets = "FormalConjectures" | | testDriver = "FormalConjecturesTest" | | | | leanOptions | | Pretty-prints fun a ↦ b | | pp.unicode.fun = true | | Don't assume a typo is a new variable | | autoImplicit = false | | relaxedAutoImplicit = false | | our own linters which we don't want to force upon downstream packages | | weak.linter.style.copyright.formalConjectures = true | | weak.linter.style.namespace = true | | | | require | | name = "mathlib" | | scope = "leanprover-community" | | rev = "v4.27.0" | | | | We make this a separate library so that we can apply different lean options. | | lean lib | | name = "FormalConjecturesForMathlib" | | | | lean lib | | name = "FormalConjecturesTest" | | lean lib.leanOptions | | Switch off warnings generated by sorry | | warn.sorry = false | | | | lean lib | | name = "FormalConjectures" | | globs = "FormalConjectures.+" | | lean lib.leanOptions | | Switch off warnings generated by sorry | | warn.sorry = false | | our own linters which only make sense for the problems themselves | | weak.linter.style.ams attribute = true | | weak.linter.style.category attribute = true | | weak.linter.style.moduleDocstring = true | | | | lean exe | | name = "extract names" | | srcDir = "scripts" | | root = "extract names" | | exeName = "extract names" | | supportInterpreter = true | | Dev: | | Checker.lean | | TestChunk.lean | | | | Submission: | | KBench.lean | | Spec.lean | | | | | | 138 --- ASSISTANT --- | | I'm checking whether Dev/Checker.lean has any imports at the top, and I realize it must import FormalConjectures.Util.ProblemImports to access the A306477 and Mathlib components. Let me verify this and then generate the necessary blobs before writing Checker5. | | bash | | | | cd /workspace/leanproject && head -20 Dev/Checker.lean && grep -n "choose4 eq\|descFactorial" Dev/Checker.lean | head | | | | | | 138 --- TOOL bash --- | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | | | /- Kernel-friendly checker that a given N has no representation | | N = T w + C4 x + C6 y + C8 z | | where T w = w+2 w+1 /2, C4 x = x x+1 x+2 x+3 /24, | | C6 y = y⋯ y+5 /720, C8 z = z⋯ z+7 /40320. -/ | | | | namespace D | | | | /-- balanced bounded forall: allB p f a = true iff p i for all i ∈ a, a + 2^f . -/ | | def allB p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | p | | fun f ih a = ih a .and ih Nat.add a Nat.pow 2 f | | fuel | | | | theorem allB zero p : Nat → Bool a : Nat : allB p 0 a = p a := rfl | | | | theorem allB succ p : Nat → Bool f a : Nat : | | 325:theorem choose4 eq x : Nat : x+3 .choose 4 = c4 x := by | | 326: rw Nat.choose eq descFactorial div factorial, c4 def, p4 def | | 328: simp Nat.descFactorial | | 332: rw Nat.choose eq descFactorial div factorial, c6 def, p6 def | | 334: simp Nat.descFactorial | | 338: rw Nat.choose eq descFactorial div factorial, c8 def, p8 def | | 340: simp Nat.descFactorial | | 368: rw choose2 eq, choose4 eq, choose6 eq, choose8 eq | | 420: rw ← choose4 eq, ← choose4 eq, d3 | | | | | | 139 --- ASSISTANT --- | | I'm creating the Dev/Blobs.lean file with three literal definitions for the v5 version. | | bash | | | | cd /tmp && python3 - <<'EOF' | | import pickle | | FLB,OFFB,SELB=pickle.load open "/tmp/blobs.pkl","rb" | | with open "/workspace/leanproject/Dev/Blobs.lean","w" as f: | | f.write "import FormalConjectures.Util.ProblemImports\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def FLB : Nat := %d\n" % FLB | | f.write "def OFFB : Nat := %d\n" % OFFB | | f.write "def SELB : Nat := %d\n" % SELB | | f.write "end D\n" | | print "sizes: FLB %d digits, OFFB %d, SELB %d" % len str FLB ,len str OFFB ,len str SELB | | EOF | | | | | | 139 --- TOOL bash --- | | <stdout </stdout | | <stderr Traceback most recent call last : | | File "<stdin ", line 7, in <module | | ValueError: Exceeds the limit 4300 digits for integer string conversion; use sys.set int max str digits to increase the limit | | </stderr | | <returncode 1</returncode | | | | 140 --- ASSISTANT --- | | bash | | | | cd /tmp && python3 - <<'EOF' | | import pickle,sys | | sys.set int max str digits 2000000 | | FLB,OFFB,SELB=pickle.load open "/tmp/blobs.pkl","rb" | | with open "/workspace/leanproject/Dev/Blobs.lean","w" as f: | | f.write "import FormalConjectures.Util.ProblemImports\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def FLB : Nat := %d\n" % FLB | | f.write "def OFFB : Nat := %d\n" % OFFB | | f.write "def SELB : Nat := %d\n" % SELB | | f.write "end D\n" | | print "digits: FLB %d, OFFB %d, SELB %d" % len str FLB ,len str OFFB ,len str SELB | | EOF | | | | | | 140 --- TOOL bash --- | | digits: FLB 271, OFFB 1625, SELB 617873 | | | | | | 141 --- ASSISTANT --- | | I need to figure out how Dev.Checker imports work in this Lean project, since Dev isn't a lake library and the import path resolution depends on LEAN PATH including the build directories. Let me check how TestChunk handles importing Checker to understand the pattern. | | bash | | | | cd /workspace/leanproject && head -3 Dev/TestChunk.lean; ls .lake/build/lib/lean/ 2 /dev/null | head | | | | | | 141 --- TOOL bash --- | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | | | FormalConjectures | | FormalConjecturesForMathlib | | FormalConjecturesForMathlib.ilean | | FormalConjecturesForMathlib.ilean.hash | | FormalConjecturesForMathlib.ir | | FormalConjecturesForMathlib.ir.hash | | FormalConjecturesForMathlib.olean | | FormalConjecturesForMathlib.olean.hash | | FormalConjecturesForMathlib.olean.private | | FormalConjecturesForMathlib.olean.private.hash | | | | | | 142 --- ASSISTANT --- | | TestChunk is self-contained and compiles directly without needing Checker, so I could add Dev as a lake library to enable olean caching instead of recompiling everything each time. I'm considering adding a lean lib entry to the lakefile with a glob pattern for Dev files, though I'm worried that modifying the lake config might trigger a full rebuild. | | | | A safer approach would be to manually precompile the modules: I'll create a devlib directory, compile Blobs.lean and Checker.lean to olean files there, then set LEAN PATH to include devlib so that imports like import Blobs resolve correctly. Then Checker5 can import both Checker and Blobs, though I need to make sure those modules themselves can resolve their dependencies on FormalConjectures.Util.ProblemImports. Writing Checker5.lean... I'm checking what lemmas exist for relating descending factorials and regular factorials, then setting up the key step theorem that shows how c4 shifts by a constant when x increases by 2700, using the polynomial relationship I derived for p4. | | | | For the proof, I need to handle the nonlinear polynomial term R carefully—omega won't work directly on cubic expressions, so I'll generalize R as an atomic variable before applying omega to the linear relationships between c4 values and p4 values. | | | | Now I'm working on the periodicity property, establishing that c4 x modulo 225 depends only on x modulo 2700. | | | | Proving the auxiliary lemma by induction on q, where the base case is trivial and the inductive step uses the recurrence relation c4 A+2700 = c4 A + 225 R to show that adding 2700 preserves the residue modulo 225—omega handles this since 225 is a literal and R becomes an atom. | | | | Now I'm defining helper functions for extracting bit fields and computing values based on bit manipulations: one extracts a 4-bit field from a lookup table, another computes a value by shifting and masking bits from two separate lookup tables, and a third function is being set up to work with these extracted values. Completing the binary search logic with a midpoint calculation, then realizing that using let bindings for intermediate values would be cleaner and help the kernel optimize the computation. The kernel substitutes let-bound terms directly into the body, so when mid appears in multiple branches, each occurrence gets re-evaluated separately rather than cached — but since only one branch survives the conditional, it's a minor inefficiency comparable to what the previous version handled fine. Now I'm moving on to prove the soundness theorem for the binary search algorithm. When the condition is false, I'm computing the midpoint and checking if the element matches there, then recursing into the appropriate half using the induction hypothesis to find the element in the valid range. The unfolding of the recursive step works by definitional equality since we're just reducing the natural number successor. Now I'm defining a wrapper function that extracts the flag and bit array from the input and applies the binary search. I'm working through the proof by introducing the hypothesis and using the soundness lemma for allBH , then I need to establish that Nat.ble 225 a evaluates to false since a < 225 , which I can derive using the boolean comparison lemmas and omega to handle the arithmetic. Realizing that cbof a gets recomputed inside the lambda for each e call—that's 921K unnecessary evaluations. I need to keep it as a let-binding outside the lambda so it's computed once, but I'm worried the kernel's zeta substitution might still inline it and force re-evaluation at each step anyway. ked: in the allBH kernel, each leaf re-evaluates the 8W+1 expression two cheap operations , but the cbof computation involves a GMP shift on 2Mbit data plus a bitwise land with a 6144-bit power, which costs maybe 10-30μs per leaf evaluation — that overhead adds up across all the e-leaves. | | | | The real problem emerges at the RUNTIME level: leafX5 receives CB as a substituted argument and re-evaluates it across all 54M leaves, which would add 27 minutes of computation. I need actual sharing rather than just syntactic substitution. The challenge is that the CBN kernel can only share through the tree structure itself, so I'd need to either restructure the tree to carry CB as a Nat.rec argument which hits the same substitution problem or make the cbof computation itself cheap by splitting the SELB definition into separate cases to avoid the expensive shifts at the leaf level. | | | | But splitting SELB into 225 separate definitions creates a function with 225 conditional branches, which means 112 structural steps on average per call—that's 300+ microseconds worse. A better approach is a two-level blob strategy: instead of substituting the full offset per leaf, I precompute a small offset table OFFB, only 5400 bits and have each leaf extract its slot directly from SELB using a global offset computed from OFFB with a cheap shift-and-mask operation on the small blob, then one final shift on the 2Mbit SELB itself. | | | | The problem is that accessing SELB per leaf still requires a bignum right-shift on 250KB of data—memory bandwidth limits this to 10-25 microseconds per leaf, and with 54 million leaves that balloons to 9-22 minutes. Instead, I should avoid per-leaf SELB access entirely by having the tree itself walk the blob: pass a compressed bit pattern down the tree, halving it at each level. Each node receives a literal bit pattern and splits it between its children by masking and shifting the appropriate portions. | | | | But wait—if I'm substituting the bit pattern expression unevaluated into the recursive calls, then call-by-name semantics means the entire chain of shifts and masks gets re-evaluated at every leaf, multiplying the work by tree depth. The root receives the original expression, and each leaf ends up re-computing the full sequence of nested shifts on the original 2Mbit value rather than receiving a pre-computed smaller chunk. | | | | Now I'm wondering whether the kernel's weak head normal form cache actually memoizes results by pointer identity—if it does, that could prevent some redundant re-evaluation, but I'm not sure if Lean's kernel actually implements that. The empirical evidence from my experiments shows that running these chain-state loops multiple times per kernel call causes catastrophic slowdowns, though the root cause remains unclear—possibly related to how the whnf cache behaves. When I measure the leaf cost at around 110 microseconds for a complex expression involving nested operations on large subexpressions, I can't definitively tell whether caching is actually helping or if the computation would take the same time anyway given the relatively small number of extra operations involved. I need to run a direct experiment to distinguish between these possibilities. | | | | My plan is to benchmark two scenarios: one where all leaves share a large let-bound expression, and another without it. This will reveal whether the kernel is actually caching and reusing that shared value. If there's no caching happening, my fallback approach would be to either limit per-leaf operations to just a couple of shifts and logical operations on the 2-megabit blob which would add 20-50 microseconds per leaf—too slow , or to split the blob into eight smaller chunks indexed by address range, so each leaf only operates on about 31 kilobytes and the shift operation drops to around 3 microseconds. | | | | For the smaller blob approach, selecting which chunk involves a conditional chain of eight branches based on the address bits, which is cheap structurally. Each leaf still needs to recompute its address value using the same W-expression chain as before, but that's only about ten operations. The added cost per leaf would be the offset lookup, the selection conditions, the 31-kilobit shift, and a final logical operation—roughly eight additional operations totaling maybe 35 microseconds, though I'm uncertain about that estimate. Reconsidering whether I even need to store slot values in the blob at all—what if the leaf just recomputes whether a slot is free by checking the constraint directly? That would avoid the blob lookup entirely, but enumerating all 2700 possible values and testing each one balloons the cost to 135ms, which is the same dead-end as the table approach I already rejected. Specializing the code per pair isn't viable either with 55K pairs to handle. | | | | Actually, looking at how Lean's kernel works: it does cache weak-head-normal forms using a pointer-keyed map, and when let-bound values get instantiated, they're pointer-shared so the cache hits within a single kernel evaluation. But the real problem is that between different kernel invocations, those pointers diverge. | | | | So in the case of let CB := cbof a; tree using CB — after zeta reduction, all references to CB point to the same expression object, meaning the first leaf evaluates the cbof chain once and caches it, while subsequent leaves get cache hits essentially for free. This aligns with the measurements I saw. The earlier mystery about chain-state being catastrophically slow across multiple runs is a separate issue: different theorem invocations rebuild the expressions from scratch, losing that sharing. | | | | The whnf cache stores the final result, so a cbof expression reduces to a literal and stays cached. | | | | Now looking at how tree nodes work: when a leaf applies a function p to a literal e , beta-instantiation rebuilds the function body with that literal substituted in, creating new pointers for any nodes containing e . But the CB subtree pointer stays unchanged since CB has no loose bound variables depending on the leaf variable — so the whnf cache hit still applies. The design works as long as big computations like CB are structured as lambda-captured values at the outer level, not depending on the leaf variable. I should keep let CB := cbof a at the xtreeOK5 level along with msk, xcap, A8, and f. | | | | For the proof side, I need to handle how compA unfolds in Lean: using simp only compA will produce the let-expression, and simp's zeta reduction should automatically reduce those lets when needed. In comp spec, I can unfold compA to get the lets expanded, then relate the structural properties back to the original definition. | | | | Now I'm moving on to verify the benchmark question empirically—the whnf cache should handle the performance, but I'll test it directly by building the real implementation and benchmarking against realistic data. I'm also confirming that COMP works correctly with the per-a CB let binding. | | | | Defining leafX5 function... Completing the soundness proof for leafX5 by substituting the expressions for e and x, then handling the case analysis on the bounds conditions to derive the contradiction that t2 w + c4 x ≠ W. I need to be careful about how I represent the multiplication in the hypothesis—using Nat.mul 2700 k consistently rather than mixing notations, and structuring x as an explicit sum so the caller can normalize it easily. Now I'm defining the xtreeOK5 function that computes A8 from W, extracts the residue modulo 225, looks up the corresponding flag and callback, and sets up the Newton iteration for the capacity check... | | | | Continuing with the bounds validation... | | | | For the soundness proof, I'll need to case-split on whether c4 2700 ≤ W holds, then use the fact that t2 is always at least one to derive the contradiction. | | | | Now I'm unpacking the conjunction from xtreeOK5 to extract the three key hypotheses about the tree structure, coverage, and capacity bounds. I'll introduce abbreviations to manage the increasingly complex arithmetic expressions, particularly around the modular arithmetic involving 8W+1 and 225. | | | | From the capacity bound, if x exceeds xcap then c4 x would exceed c4 xcap+1 , which contradicts our assumption that c4 x + 1 ≤ W. For the coverage bound, I need to work through the constraint on 2700·2^ fx to establish the necessary inequality. | | | | Now I'm setting up the division: x = 2700k + e where e is the remainder and k is the quotient, then using omega to verify that k < 2^ fx−f follows from the bound on x. Finally, I'll split on whether a and e satisfy the colFree predicate to determine which case applies. I need to split on the condition early to handle the two cases where fx evaluates to either f+1 or f, then either write separate proofs for each branch or define an auxiliary lemma to unify the logic and avoid duplication. Continuing with the proof structure by normalizing the spelling and applying the helper lemma to both branches — the conditional cases resolve to concrete expressions, and I'm using simplification rules to bridge the natural number notation. For the colFree case, I'm setting up a modular arithmetic argument where v is defined as 8W+1 minus a scaled term, which stays valid when the scaling factor is less than W. Now I'm checking the colFree predicate to verify that when it returns true, the bitwise operations confirm no perfect square equals v—specifically, I need to trace through the beq land zero lemma to ensure the index is correctly computed as v % 225 and that the mask properly eliminates all quadratic residues. | | I'm checking the exact statements of beq land zero , maskK1 all , and sqTest2 in Checker.lean to understand how the kernel whnf caching for let-shared big values works. | | bash | | | | cd /workspace/leanproject && sed -n '/def R1/,/def sqTest2/p' Dev/Checker.lean | grep -v "^def K" | head -60 | | | | | | 142 --- TOOL bash --- | | def R1 : Nat := 225 | | def R2 : Nat := 539 | | def R3 : Nat := 221 | | def R4 : Nat := 437 | | | | set option maxHeartbeats 1000000 in | | theorem sqAllK1 : sqAll R1 K1 8 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllK2 : sqAll R2 K2 10 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllK3 : sqAll R3 K3 8 = true := by decide +kernel | | set option maxHeartbeats 1000000 in | | theorem sqAllK4 : sqAll R4 K4 9 = true := by decide +kernel | | | | theorem maskK1 all : ∀ j : Nat, maskBit K1 j j % R1 = true := | | sqAll sound by norm num R1 by norm num R1 sqAllK1 | | theorem maskK2 all : ∀ j : Nat, maskBit K2 j j % R2 = true := | | sqAll sound by norm num R2 by norm num R2 sqAllK2 | | theorem maskK3 all : ∀ j : Nat, maskBit K3 j j % R3 = true := | | sqAll sound by norm num R3 by norm num R3 sqAllK3 | | theorem maskK4 all : ∀ j : Nat, maskBit K4 j j % R4 = true := | | sqAll sound by norm num R4 by norm num R4 sqAllK4 | | | | def sqTest2 v : Nat : Bool := | | | | | | 143 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && grep -n "def maskBit\|theorem beq land zero" -A 12 Dev/Checker.lean | sed -n 1,30p | | | | | | 143 --- TOOL bash --- | | 98:def maskBit mask u : Nat : Bool := Nat.beq Nat.land Nat.shiftRight mask u 1 1 | | 99- | | 100-def sqAll q mask : Nat fq : Nat : Bool := | | 101- allB fun u = maskBit mask Nat.mod Nat.mul u u q fq 0 | | 102- | | 103-theorem sqAll sound {q mask fq : Nat} hq : 0 < q hle : q ≤ 2^fq | | 104- h : sqAll q mask fq = true : ∀ j : Nat, maskBit mask j j % q = true := by | | 105- intro j | | 106- have hj : j % q < q := Nat.mod lt hq | | 107- have h2 := allB sound fq 0 h j % q Nat.zero le by omega | | 108- have e : j % q j % q % q = j j % q := by rw ← Nat.mul mod | | 109- have h3 : maskBit mask j % q j % q % q = true := h2 | | 110- rwa e at h3 | | -- | | 750:theorem beq land zero {K q v : Nat} hall : ∀ j : Nat, maskBit K j j % q = true | | 751- hb : Nat.beq Nat.land Nat.shiftRight K Nat.mod v q 1 0 = true : | | 752- ∀ j : Nat, j j ≠ v := by | | 753- intro j hj | | 754- have m := hall j | | 755- rw hj, maskBit at m | | 756- simp only mod eqn at hb | | 757- rw Nat.beq eq at m hb | | 758- omega | | 759- | | 760-theorem sqTest2 sound {v : Nat} h : sqTest2 v = true : ∀ j : Nat, j j ≠ v := by | | 761- intro j hj | | 762- cases h2 : Nat.beq Nat.land Nat.shiftRight K2 Nat.mod v R2 1 0 with | | | | | | 144 --- ASSISTANT --- | | For the colFree case, I need to rewrite the hypothesis using the fact that g225 a e equals v modulo 225, which lets me apply the beq land zero lemma in the right form. | | | | Now I'm planning out the full Checker5.lean file structure: starting with c4 mul24 and the period lemmas, then the modular arithmetic helper, followed by the core definitions fla, cbof, g225, colFree , then the soundness proof for bsA, and finally the comparison and computation functions. | | | | For comp true, I'm considering whether to put it last or defer it to a separate benchmark file since it's computationally expensive—I could temporarily use it as a hypothesis during development to speed up iteration, then commit to the full kernel computation once the rest compiles. | | | | Actually, a cleaner approach: move the blob definitions and comp true into a dedicated development module that gets compiled once to an object file, then import it into the main checker file for fast iteration. This means gathering all the dependent definitions—the flag functions, color-freeness check, and the composition axiom—into one place, compiling that once, and keeping the proof work in a separate file that can iterate quickly. | | | | Let me get the devlib set up and start compiling. I should also check whether Nat.factorial dvd descFactorial is already available in the standard library. | | I'm setting up olean-based layering for fast iteration and writing the v5 definitions file. | | bash | | | | cd /workspace/leanproject && mkdir -p devlib && cat /tmp/t1.lean <<'EOF' | | import Mathlib | | example n : Nat : 24:Nat ∣ n n+1 n+2 n+3 := by | | have h := Nat.factorial dvd descFactorial n+3 4 | | simp Nat.descFactorial, Nat.factorial at h ⊢ | | convert h using 1 <; ring | | example A B : Nat h : B ≤ A : A - B % 225 = A % 225 + 1800 - B % 225 % 225 := by omega | | EOF | | timeout 280 lake env lean /tmp/t1.lean 2 &1 | head | | | | | | 144 --- TOOL bash --- | | /tmp/t1.lean:5:20: warning: Used tac1 <; tac2 where tac1; tac2 would suffice | | | | Note: This linter can be disabled with set option linter.unnecessarySeqFocus false | | | | | | 145 --- ASSISTANT --- | | Both approaches work—the factorial divisibility lemma and omega's modular arithmetic reasoning handle this. Now I need to compile Checker.lean to its object file and then move on to writing V5Defs.lean. | | Both key lemmas are working, so I'll compile Checker.lean to an olean file and then write out the V5 defs file. | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env lean Dev/Checker.lean -o devlib/Checker.olean' /tmp/chk.log 2 &1 & | | cat Dev/V5Defs.lean <<'EOF' | | import Checker | | set option linter.style.moduleDocstring false | | set option maxHeartbeats 1000000 | | | | /- v5 definitions: SEL-blob mod-225, period-2700 column-filtered x enumeration. -/ | | | | namespace D | | | | def fla a : Nat : Nat := Nat.land Nat.shiftRight FLB Nat.mul 4 a 15 | | | | def cbof a : Nat : Nat := | | Nat.land Nat.shiftRight SELB Nat.land Nat.shiftRight OFFB Nat.mul 24 a 16777215 | | Nat.sub Nat.pow 2 Nat.mul 12 Nat.pow 2 fla a 1 | | | | def g225 a e : Nat : Nat := | | Nat.mod Nat.sub Nat.add a 1800 Nat.mod Nat.mul 8 c4 e 225 225 | | | | def colFree a e : Nat : Bool := | | Nat.beq Nat.land Nat.shiftRight K1 g225 a e 1 0 | | | | /-- binary search for slot value e in packed 12-bit slot array CB , range lo,hi . -/ | | def bsA CB e : Nat : Nat → Nat → Nat → Bool := fun fuel = | | Nat.rec motive := fun = Nat → Nat → Bool | | fun = false | | fun ih lo hi = | | cond Nat.ble hi lo false | | let mid := Nat.div Nat.add lo hi 2 | | let s := Nat.land Nat.shiftRight CB Nat.mul 12 mid 4095 | | cond Nat.beq s e true | | cond Nat.blt s e ih Nat.add mid 1 hi ih lo mid | | fuel | | | | theorem bsA sound {CB e : Nat} : ∀ f lo hi : Nat , bsA CB e f lo hi = true → | | ∃ i, lo ≤ i ∧ i < hi ∧ Nat.land Nat.shiftRight CB Nat.mul 12 i 4095 = e := by | | intro f | | induction f with | | | zero = intro lo hi h; exact absurd h by simp bsA | | | succ f ih = | | intro lo hi h | | have hs : bsA CB e f+1 lo hi = | | cond Nat.ble hi lo false | | cond Nat.beq Nat.land Nat.shiftRight CB Nat.mul 12 Nat.div Nat.add lo hi 2 4095 e true | | cond Nat.blt Nat.land Nat.shiftRight CB Nat.mul 12 Nat.div Nat.add lo hi 2 4095 e | | bsA CB e f Nat.add Nat.div Nat.add lo hi 2 1 hi | | bsA CB e f lo Nat.div Nat.add lo hi 2 := rfl | | rw hs at h | | cases hlo : Nat.ble hi lo with | | | true = rw hlo at h; simp at h | | | false = | | rw hlo, cond false at h | | have hlt : lo < hi := by | | have : ¬ hi ≤ lo := by rw ← Nat.ble eq, hlo ; simp | | omega | | set mid := Nat.div Nat.add lo hi 2 with hmid | | have hmr : lo ≤ mid ∧ mid < hi := by | | simp only hmid, div eqn, add eqn ; omega | | cases hb : Nat.beq Nat.land Nat.shiftRight CB Nat.mul 12 mid 4095 e with | | | true = | | rw Nat.beq eq at hb | | exact ⟨mid, hmr.1, hmr.2, hb⟩ | | | false = | | rw hb, cond false at h | | cases hc : Nat.blt Nat.land Nat.shiftRight CB Nat.mul 12 mid 4095 e with | | | true = | | rw hc, cond true at h | | obtain ⟨i, h1, h2, h3⟩ := ih h | | have : Nat.add mid 1 = mid + 1 := rfl | | rw this at h1 | | exact ⟨i, by omega, h2, h3⟩ | | | false = | | rw hc, cond false at h | | obtain ⟨i, h1, h2, h3⟩ := ih h | | exact ⟨i, h1, by omega, h3⟩ | | | | def compA a : Nat : Bool := | | let f := fla a | | let CB := cbof a | | allBH fun e = cond Nat.ble 2700 e true | | cond colFree a e true bsA CB e Nat.add f 1 0 Nat.pow 2 f 12 0 | | | | def COMP : Bool := allBH fun a = cond Nat.ble 225 a true compA a 8 0 | | | | set option maxHeartbeats 4000000 in | | theorem comp true : COMP = true := by decide +kernel | | | | end D | | EOF | | echo written | | | | | | 145 --- TOOL bash --- | | written | | | | | | 146 --- ASSISTANT --- | | I'm realizing V5Defs needs to import Checker, but the blob definitions live in a separate Blobs.lean file. I should have V5Defs import both modules and make sure Blobs.olean gets compiled alongside it. | | bash | | | | cd /workspace/leanproject && sed -i 's/^import Checker$/import Checker\nimport Blobs/' Dev/V5Defs.lean && head -3 Dev/V5Defs.lean; sed -i 's/^import FormalConjectures.Util.ProblemImports$/import Checker/' Dev/Blobs.lean && head -3 Dev/Blobs.lean | cut -c1-60; tail -3 /tmp/chk.log | | | | | | 146 --- TOOL bash --- | | import Checker | | import Blobs | | set option linter.style.moduleDocstring false | | import Checker | | set option linter.style.moduleDocstring false | | namespace D | | | | | | 147 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && sleep 60; cat /tmp/chk.log; ls -la devlib/ | | | | | | 147 --- TOOL bash --- | | Dev/Checker.lean:82:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/Checker.lean:82:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/Checker.lean:88:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/Checker.lean:88:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/Checker.lean:94:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/Checker.lean:94:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | | | real 0m16.616s | | user 0m16.818s | | sys 0m2.455s | | total 1884 | | drwxr-xr-x. 2 root root 27 Aug 2 22:22 . | | drwxr-xr-x. 1 root root 62 Aug 2 22:21 .. | | -rw-r--r--. 1 root root 1926944 Aug 2 22:22 Checker.olean | | | | | | 148 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Blobs.lean -o devlib/Blobs.olean" && time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/V5Defs.lean -o devlib/V5Defs.olean"' /tmp/v5defs.log 2 &1 & echo bg; tail -1 /tmp/scan99b.err | | | | | | 148 --- TOOL bash --- | | bg | | block 1/35 done marks=165241602558 zeros=0 | | | | | | 149 --- ASSISTANT --- | | While the compilation runs, I'm moving on to write the math lemmas and soundness proofs in Checker5.lean. I'm also noticing that scan99b is progressing slower than expected—it's on block 2 now and competing with the Lean compilation for resources, which could stretch the total runtime to 5-10 hours across all 34 blocks. | | Now write the main v5 proofs file while that compiles. | | bash | | | | cd /workspace/leanproject && cat Dev/Checker5.lean <<'EOF' | | import V5Defs | | set option linter.style.moduleDocstring false | | set option maxHeartbeats 1000000 | | | | namespace D | | | | /- periodicity of c4 mod 225 with period 2700 -/ | | | | theorem c4 mul24 x : Nat : 24 c4 x = p4 x := by | | have hd : p4 x = x+3 .descFactorial 4 := by | | simp Nat.descFactorial, p4 def ; ring | | have h24 : 24:Nat ∣ p4 x := by | | rw hd | | have := Nat.factorial dvd descFactorial x+3 4 | | simpa Nat.factorial using this | | rw c4 def | | exact Nat.mul div cancel' h24 | | | | theorem c4 step x : Nat : | | c4 x + 2700 = c4 x + 225 2 x^3 + 8109 x^2 + 14604311 x + 9863384853 := by | | have hp : p4 x + 2700 = p4 x + 5400 2 x^3 + 8109 x^2 + 14604311 x + 9863384853 := by | | simp only p4 def ; ring | | have h1 := c4 mul24 x+2700 | | have h2 := c4 mul24 x | | set R := 2 x^3 + 8109 x^2 + 14604311 x + 9863384853 | | omega | | | | theorem c4 period aux : ∀ q e : Nat , c4 2700 q + e % 225 = c4 e % 225 := by | | intro q | | induction q with | | | zero = intro e; norm num | | | succ q ih = | | intro e | | have h : 2700 q+1 + e = 2700 q + e + 2700 := by ring | | rw h, c4 step | | have := ih e | | omega | | | | theorem c4 period x : Nat : c4 x % 225 = c4 x % 2700 % 225 := by | | conv lhs = rw show x = 2700 x / 2700 + x % 2700 by omega | | exact c4 period aux | | | | /-- key congruence: for c4 x ≤ W , 8W+1 - 8 c4 x % 225 = g225 8W+1 %225 x%2700 . -/ | | theorem v mod eq W x : Nat hle : c4 x ≤ W : | | 8 W+1 - 8 c4 x % 225 = g225 8 W+1 % 225 x % 2700 := by | | have hper := c4 period x | | have h8 : 8 c4 x % 225 = 8 c4 x % 2700 % 225 := by | | rw Nat.mul mod, hper, ← Nat.mul mod | | rw g225 | | simp only mod eqn, sub eqn, add eqn, mul eqn | | omega | | | | /- comp spec -/ | | | | theorem comp spec : ∀ a, a < 225 → ∀ e, e < 2700 → colFree a e = false → | | bsA cbof a e Nat.add fla a 1 0 Nat.pow 2 fla a = true := by | | intro a ha e he hcf | | have h := allBH sound 0 comp true a Nat.zero le by norm num; omega | | have hble : Nat.ble 225 a = false := by | | cases hb : Nat.ble 225 a with | | | true = rw Nat.ble eq at hb; omega | | | false = rfl | | rw hble, cond false at h | | simp only compA at h | | have h2 := allBH sound 0 h e Nat.zero le by norm num; omega | | have hble2 : Nat.ble 2700 e = false := by | | cases hb : Nat.ble 2700 e with | | | true = rw Nat.ble eq at hb; omega | | | false = rfl | | rw hble2, cond false, hcf, cond false at h2 | | exact h2 | | | | /- the v5 leaf -/ | | | | def leafX5 A8 CB f msk xcap : Nat j : Nat : Bool := | | let e := Nat.land Nat.shiftRight CB Nat.mul 12 Nat.land j msk 4095 | | cond Nat.ble 2700 e true | | let x := Nat.add Nat.mul 2700 Nat.shiftRight j f e | | cond Nat.blt xcap x true | | let t := Nat.mul x Nat.add x 3 | | let c := Nat.div Nat.mul t Nat.add t 2 24 | | let v := Nat.sub A8 Nat.mul 8 c | | cond Nat.ble v 1 true sqTest2 v | | | | theorem leafX5 sound {W CB f msk xcap j : Nat} | | h : leafX5 8 W+1 CB f msk xcap j = true | | e x : Nat | | hedef : e = Nat.land Nat.shiftRight CB Nat.mul 12 Nat.land j msk 4095 | | hxdef : x = 2700 Nat.shiftRight j f + e | | helt : e < 2700 hxle : x ≤ xcap : | | ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | have hc4 := c4 alt x | | rw leafX5 at h | | rw ← hedef at h | | have hble : Nat.ble 2700 e = false := by | | cases hb : Nat.ble 2700 e with | | | true = rw Nat.ble eq at hb; omega | | | false = rfl | | rw hble, cond false at h | | have hxdef' : Nat.add Nat.mul 2700 Nat.shiftRight j f e = x := by | | simp only add eqn, mul eqn ; omega | | rw hxdef' at h | | have hblt : Nat.blt xcap x = false := by | | cases hb : Nat.blt xcap x with | | | true = rw Nat.blt eq at hb; omega | | | false = rfl | | rw hblt, cond false at h | | simp only hc4 at h | | cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | | true = | | rw Nat.ble eq at hb | | simp only sub eqn, mul eqn at hb | | omega | | | false = | | rw hb, cond false at h | | have hlt : ¬ Nat.sub 8 W+1 Nat.mul 8 c4 x ≤ 1 := by | | rw ← Nat.ble eq, hb ; simp | | simp only sub eqn, mul eqn at hlt | | have hv : Nat.sub 8 W+1 Nat.mul 8 c4 x = 2 w+3 2 w+3 := by | | simp only sub eqn, mul eqn | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | rw hv at h | | exact sqTest2 sound h 2 w+3 rfl | | | | /- the v5 x-tree -/ | | | | def xtreeOK5 W : Nat : Bool := | | let A8 := Nat.add Nat.mul 8 W 1 | | let a := Nat.mod A8 225 | | let f := fla a | | let CB := cbof a | | let xcap := newton newton Nat.mul 24 W | | let fx := cond Nat.ble c4 2700 W Nat.add f 1 f | | allBH leafX5 A8 CB f Nat.sub Nat.pow 2 f 1 xcap fx 0 .and | | Nat.blt W c4 Nat.mul 2700 Nat.pow 2 Nat.sub fx f .and | | Nat.blt W c4 Nat.add xcap 1 | | | | theorem xtree5 core {W fx : Nat} | | htree : allBH leafX5 8 W+1 cbof 8 W+1 % 225 fla 8 W+1 % 225 | | 2 ^ fla 8 W+1 % 225 - 1 newton newton 24 W fx 0 = true | | hf : fla 8 W+1 % 225 ≤ fx | | hcov : W < c4 2700 2 ^ fx - fla 8 W+1 % 225 | | hcap : W < c4 newton newton 24 W + 1 : | | ∀ w x, t2 w + c4 x ≠ W := by | | intro w x heq | | have ht := t2 ge one w | | set a := 8 W+1 % 225 with hadef | | set f := fla a with hfdef | | set xcap := newton newton 24 W with hxcapdef | | -- x ≤ xcap | | have hxle : x ≤ xcap := by | | by contra hgt | | have : c4 xcap + 1 ≤ c4 x := c4 mono by omega | | omega | | -- x < 2700 2^ fx-f | | have hxlt : x < 2700 2 ^ fx - f := by | | by contra hgt | | have : c4 2700 2 ^ fx - f ≤ c4 x := c4 mono by omega | | omega | | set e := x % 2700 with hedef | | set k := x / 2700 with hkdef | | have helt : e < 2700 := by omega | | have ha : a < 225 := Nat.mod lt by norm num | | -- the value v and its residue | | have hc4W : c4 x < W := by omega | | cases hcf : colFree a e with | | | true = | | -- column is square-free mod 225: contradiction with v = 2w+3 ^2 | | have hv : 8 W+1 - 8 c4 x = 2 w+3 2 w+3 := by | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | have hmod := v mod eq W x le of lt hc4W | | rw colFree at hcf | | have hnots : ∀ j : Nat, j j ≠ 8 W+1 - 8 c4 x := by | | apply beq land zero maskK1 all v := 8 W+1 - 8 c4 x | | have : Nat.mod 8 W+1 - 8 c4 x R1 = g225 a e := by | | simp only mod eqn, R1 | | rw hmod | | rw this | | exact hcf | | exact hnots 2 w+3 hv.symm | | | false = | | -- column has candidates: covered by the SEL enumeration | | have hbs := comp spec a ha e helt hcf | | obtain ⟨i, hi0, hilt, hslot⟩ := bsA sound hbs | | -- j = k 2^f + i is in the tree | | have hklt : k < 2 ^ fx - f := by omega | | have hjlt : k 2 ^ f + i < 2 ^ fx := by | | have hpow : 2:Nat ^ fx = 2 ^ fx - f 2 ^ f := by | | rw ← Nat.pow add | | congr 1 | | omega | | simp only pow eqn at hilt | | calc k 2 ^ f + i < k 2 ^ f + 2 ^ f := by omega | | = k + 1 2 ^ f := by ring | | ≤ 2 ^ fx - f 2 ^ f := Nat.mul le mul right by omega | | = 2 ^ fx := hpow.symm | | have hleaf := allBH sound 0 htree k 2 ^ f + i Nat.zero le by omega | | -- decode | | have hdec1 : Nat.land k 2 ^ f + i 2 ^ f - 1 = i := by | | have : Nat.land k 2 ^ f + i 2 ^ f - 1 = k 2 ^ f + i % 2 ^ f := | | Nat.and two pow sub one eq mod | | rw this | | simp only pow eqn at hilt | | rw Nat.add mul mod self left ▸ by ring nf : k 2 ^ f + i = i + 2^f k | | · rw Nat.add mul mod self left, Nat.mod eq of lt hilt | | have hdec2 : Nat.shiftRight k 2 ^ f + i f = k := by | | rw Nat.shiftRight eq div pow | | simp only pow eqn at hilt | | rw Nat.add mul div left Nat.pos pow of pos f by norm num | | · omega | | sorry | | sorry | | | | end D | | EOF | | echo written -- will iterate; cat /tmp/v5defs.log | tail -5 | | | | | | 149 --- TOOL bash --- | | written -- will iterate | | | | | | 150 --- ASSISTANT --- | | I need to carefully work through the final steps of the xtree5 core proof, particularly around how the leaf predicate interacts with the allBH sound result and making sure the structure at the end is clean without relying on sorry . | | | | The key is bridging between htree's notation with 8 W+1 and xtreeOK5's definition using Nat. spellings through simp lemmas. Then I apply leafX5 sound with the right hypotheses: the leaf predicate holds, the slot value expression matches what we need via the hdec1 decomposition where Nat.land j msk = i , and the x definition follows from hdec2 where shiftRight j f = k . The contradiction comes from showing that for all w, t2 w + c4 x ≠ W contradicts heq. | | | | For cleaning up hdec1, I'm using the modular arithmetic lemma that k n + i % n = i % n to extract i from the k 2^f + i form, which should give me the clean decomposition without messy case work. Now I'm working through the bounds checking for the recursive case — the key is that omega can handle the arithmetic with 2^fx as an atom, so I can unify the bound j < 0 + 2^fx from the recursive call with what hleaf expects. Then I apply leafX5 sound with the accumulated hypotheses about the element's definition and ordering properties. | | | | For the hedef proof, I need to show that the extracted element matches the definition by rewriting through hdec1 to simplify the mask operation land j 2^f−1 down to i , then using hslot to confirm the final expression. Proving the second lemma about right shift... I'm checking whether omega can handle the literal power 2^8 directly, or if I need to use norm num first to simplify 0 + 2^8 before applying omega . The safest approach is probably combining simp to normalize the addition and then letting omega handle the inequality with the constant-folded power. In comp spec, after simplifying with compA, the hypothesis gets zeta-reduced to show the allBH condition matching the goal exactly. For leafX5 sound, I need to rewrite with the leafX5 definition to unfold it, since it's a def rather than an equation. I'm wondering whether rw automatically beta/zeta-reduces the let-bindings after rewriting, or if the equation lemma itself already has them expanded. Looking at how the v4 code handled leafX4 sound — after the rewrite they used simp and cases on the condition, which suggests the let structure was already transparent or got expanded, so I need to figure out whether the equation lemma preserves the lets or if the rewrite tactic handles that automatically. | | | | For leafX5 sound , after rewriting with the lemma, the hypothesis will contain the expression with Nat.land j msk , and I can use a backward rewrite with hedef to substitute that exact pattern. Then I'll need to handle the addition expression similarly. Now I'm working through the algebraic substitution where c is expressed in terms of x using the formula c = t t + 2 / 24 with t = x x + 3 , which gives me the expanded form for c4 alt. I'm trying to rewrite this definition into h using simp to substitute the expanded expression for c4 x, which should simplify the conditional logic. | | Let me check the exact statement of c4 alt and newton -related helpers used in v4 proofs. | | bash | | | | cd /workspace/leanproject && grep -n "c4 alt" -A 6 Dev/Checker.lean | head -20; grep -n "Nat.mul add mod\|Nat.mul add div" .lake/packages/lean4/src 2 /dev/null | head; cat /tmp/t2.lean <<'EOF' | | import Mathlib | | example k f i : Nat h : i < 2^f : k 2 ^ f + i % 2^f = i := by | | rw Nat.mul add mod, Nat.mod eq of lt h | | example k f i : Nat h : i < 2^f : k 2 ^ f + i / 2^f = k := by | | rw Nat.mul comm k, Nat.mul add div Nat.two pow pos f , Nat.div eq of lt h | | EOF | | timeout 280 lake env lean /tmp/t2.lean 2 &1 | head; tail -5 /tmp/v5defs.log | | | | | | 150 --- TOOL bash --- | | 596:theorem c4 alt x : Nat : Nat.div Nat.mul Nat.mul x Nat.add x 3 Nat.add Nat.mul x Nat.add x 3 2 24 = c4 x := by | | 597- rw c4 def, p4 def | | 598- simp only mul eqn, add eqn, div eqn | | 599- congr 1 | | 600- ring | | 601- | | 602-theorem leafX3 sound {W x : Nat} h : leafX3 8 W+1 x = true : ∀ w, t2 w + c4 x ≠ W := by | | -- | | 605: have hc4 : Nat.div Nat.mul Nat.mul x Nat.add x 3 Nat.add Nat.mul x Nat.add x 3 2 24 = c4 x := c4 alt x | | 606- rw leafX3 at h | | 607- simp only hc4 at h | | 608- -- now h : cond Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 true sqTest = true | | 609- cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | 610- | true = | | 611- rw Nat.ble eq at hb | | -- | | 886: have hc4 := c4 alt x | | 887- rw leafX4 at h | | 888- simp only hc4 at h | | 889- cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | /tmp/t2.lean:3:6: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | ?m ?x + ?y % ?m | | in the target expression | | k 2 ^ f + i % 2 ^ f = i | | | | k f i : ℕ | | h : i < 2 ^ f | | ⊢ k 2 ^ f + i % 2 ^ f = i | | /tmp/t2.lean:4:67: error: unsolved goals | | k f i : ℕ | | | | | | 151 --- ASSISTANT --- | | I'm checking that c4 alt correctly expresses the modular arithmetic relationship, and now I need to handle the modulus operation properly—the issue is that Nat.mul add mod applies the modulus to the first factor, so I'll need to rewrite the multiplication order or find an alternative lemma that handles the form x m+y %m directly. | | bash | | | | cat /tmp/t2.lean <<'EOF' | | import Mathlib | | example k f i : Nat h : i < 2^f : k 2 ^ f + i % 2^f = i := by | | rw Nat.mul comm k, Nat.mul add mod, Nat.mod eq of lt h | | example k f i : Nat h : i < 2^f : k 2 ^ f + i / 2^f = k := by | | rw Nat.mul comm k, Nat.mul add div Nat.two pow pos f , Nat.div eq of lt h | | example a : Nat ha : a < 225 : a < 0 + 2^8 := by omega | | example n : Nat : Nat.land n 15 = n % 16 := Nat.and two pow sub one eq mod n 4 | | EOF | | cd /workspace/leanproject && timeout 280 lake env lean /tmp/t2.lean 2 &1 | head -20; tail -5 /tmp/v5defs.log | | | | | | 151 --- TOOL bash --- | | /tmp/t2.lean:4:67: error: unsolved goals | | k f i : ℕ | | h : i < 2 ^ f | | ⊢ k + 0 = k | | | | | | 152 --- ASSISTANT --- | | The modular arithmetic approach is working well—the div operation correctly leaves k + 0 = k by appending omega, omega handles the bitwise operation on 0 + 2^8 , and the bitwise AND property reduces to modulo via definitional equality without errors. The compilation is still in progress on the core definitions, so I'm now cleaning up the end of the xtree5 core section and preparing to add the soundness proofs for xtreeOK5 along with the Y and Z level definitions. | | Now let me rewrite Checker5.lean completely with the corrected ending. | | bash | | | | cd /workspace/leanproject && python3 - <<'EOF' | | content = open 'Dev/Checker5.lean' .read | | replace from " have hleaf" ... to end with corrected block | | idx = content.index ' have hleaf := allBH sound' | | new tail = ''' have hilt2 : i < 2 ^ f := by simpa only pow eqn using hilt | | have hleaf := allBH sound 0 htree k 2 ^ f + i Nat.zero le by omega | | -- decode | | have hdec1 : Nat.land k 2 ^ f + i 2 ^ f - 1 = i := by | | show k 2 ^ f + i &&& 2 ^ f - 1 = i | | rw Nat.and two pow sub one eq mod, Nat.mul comm k, Nat.mul add mod, | | Nat.mod eq of lt hilt2 | | have hdec2 : Nat.shiftRight k 2 ^ f + i f = k := by | | rw Nat.shiftRight eq div pow, Nat.mul comm k, Nat.mul add div Nat.two pow pos f , | | Nat.div eq of lt hilt2 | | have hedef : e = Nat.land Nat.shiftRight cbof a Nat.mul 12 | | Nat.land k 2 ^ f + i 2 ^ f - 1 4095 := by | | rw hdec1, hslot | | have hxdef : x = 2700 Nat.shiftRight k 2 ^ f + i f + e := by | | rw hdec2 | | omega | | exact leafX5 sound hleaf e x hedef hxdef helt hxle w heq | | | | theorem xtreeOK5 sound {W : Nat} h : xtreeOK5 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | have hh : xtreeOK5 W = true := h | | rw xtreeOK5 at hh | | simp only add eqn, mul eqn, sub eqn, pow eqn, mod eqn at hh | | rw Bool.and eq true, Bool.and eq true at hh | | obtain \u27e8htree, hcov, hcap\u27e9 := hh | | rw Nat.blt eq at hcov hcap | | cases hc : Nat.ble c4 2700 W with | | | true = | | rw hc at htree hcov | | have h1 : Nat.add fla 8 W+1 % 225 1 = fla 8 W+1 % 225 + 1 := rfl | | rw h1 at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap | | | false = | | rw hc at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap | | | | /- y and z levels -/ | | | | def leafY5 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK5 Nat.sub N b | | | | theorem leafY5 sound {N r8 y : Nat} h : leafY5 N r8 y = true : | | \u2200 w x, t2 w + c4 x + c6 y + r8 \u2260 N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : \u00ac N \u2264 r8 + c6 y := by rw \u2190 add eqn, \u2190 Nat.ble eq, hb ; simp | | simp only leafY5, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK5 sound h w x this | | | | def ytreeOK5 N fy r8 : Nat : Bool := | | allB leafY5 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | theorem ytreeOK5 sound {N fy r8 : Nat} h : ytreeOK5 N fy r8 = true : | | \u2200 w x y, t2 w + c4 x + c6 y + r8 \u2260 N := by | | intro w x y heq | | simp only ytreeOK5 at h | | rw Bool.and eq true at h | | obtain \u27e8h1, h2\u27e9 := h | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | \u00b7 exact leafY5 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | \u00b7 have hc : c6 Nat.pow 2 fy \u2264 c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | def leafZ5 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true ytreeOK5 N fy r8 | | | | theorem leafZ5 sound {N fy z : Nat} h : leafZ5 N fy z = true : | | \u2200 w x y, t2 w + c4 x + c6 y + c8 z \u2260 N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ5, hb, cond false at h | | exact ytreeOK5 sound h w x y heq | | | | theorem master5 {N fy fz : Nat} | | h : allB leafZ5 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | \u2200 w x y z, t2 w + c4 x + c6 y + c8 z \u2260 N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | \u00b7 exact leafZ5 sound allB sound 0 h z Nat.zero le by omega w x y heq | | \u00b7 rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz \u2264 c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | ''' | | new tail = new tail.encode .decode 'unicode escape' | | open 'Dev/Checker5.lean','w' .write content :idx + new tail | | print "ok" | | EOF | | tail -c 300 Dev/Checker5.lean; tail -3 /tmp/v5defs.log | | | | | | 152 --- TOOL bash --- | | ok | | eq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ5 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | real 2m24.602s | | user 2m21.854s | | sys 0m1.973s | | | | | | 153 --- ASSISTANT --- | | I'm running into an encoding issue where unicode escape decoding is mangling UTF-8 characters — the problem is that unicode escape produces latin-1 characters which then get written as UTF-8, creating double-encoding artifacts like "·" instead of the intended character. | | | | The root cause is that I was already using \u escapes in the Python string literal, so the characters were already properly interpreted by Python; then calling .encode .decode 'unicode escape' was an unnecessary extra step that converted them to latin-1, causing the mojibake when written to the file. | | | | Looking at the compile logs, Blobs.lean took over two minutes to finish — probably because elaborating those large literals is computationally expensive. Now I need to rewrite the file using a plain heredoc with quoted delimiters to preserve everything literally without any encoding tricks. | | Encoding got mangled. Let me rewrite the tail properly with a plain heredoc. | | bash | | | | cd /workspace/leanproject && python3 - <<'PYEOF' | | content = open 'Dev/Checker5.lean','rb' .read .decode 'utf-8' | | idx = content.index ' have hilt2' | | open '/tmp/head5.txt','w' .write content :idx | | print 'saved head', idx | | PYEOF | | cat /tmp/head5.txt Dev/Checker5.lean | | cat Dev/Checker5.lean <<'EOF' | | have hilt2 : i < 2 ^ f := by simpa only pow eqn using hilt | | have hleaf := allBH sound 0 htree k 2 ^ f + i Nat.zero le by omega | | -- decode | | have hdec1 : Nat.land k 2 ^ f + i 2 ^ f - 1 = i := by | | show k 2 ^ f + i &&& 2 ^ f - 1 = i | | rw Nat.and two pow sub one eq mod, Nat.mul comm k, Nat.mul add mod, | | Nat.mod eq of lt hilt2 | | have hdec2 : Nat.shiftRight k 2 ^ f + i f = k := by | | rw Nat.shiftRight eq div pow, Nat.mul comm k, Nat.mul add div Nat.two pow pos f , | | Nat.div eq of lt hilt2 | | omega | | have hedef : e = Nat.land Nat.shiftRight cbof a Nat.mul 12 | | Nat.land k 2 ^ f + i 2 ^ f - 1 4095 := by | | rw hdec1, hslot | | have hxdef : x = 2700 Nat.shiftRight k 2 ^ f + i f + e := by | | rw hdec2 | | omega | | exact leafX5 sound hleaf e x hedef hxdef helt hxle w heq | | | | theorem xtreeOK5 sound {W : Nat} h : xtreeOK5 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | have hh : xtreeOK5 W = true := h | | rw xtreeOK5 at hh | | simp only add eqn, mul eqn, sub eqn, pow eqn, mod eqn at hh | | rw Bool.and eq true, Bool.and eq true at hh | | obtain ⟨htree, hcov, hcap⟩ := hh | | rw Nat.blt eq at hcov hcap | | cases hc : Nat.ble c4 2700 W with | | | true = | | rw hc at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap | | | false = | | rw hc at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap | | | | /- y and z levels -/ | | | | def leafY5 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK5 Nat.sub N b | | | | theorem leafY5 sound {N r8 y : Nat} h : leafY5 N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp | | simp only leafY5, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK5 sound h w x this | | | | def ytreeOK5 N fy r8 : Nat : Bool := | | allB leafY5 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | theorem ytreeOK5 sound {N fy r8 : Nat} h : ytreeOK5 N fy r8 = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | simp only ytreeOK5 at h | | rw Bool.and eq true at h | | obtain ⟨h1, h2⟩ := h | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY5 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | def leafZ5 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true ytreeOK5 N fy r8 | | | | theorem leafZ5 sound {N fy z : Nat} h : leafZ5 N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ5, hb, cond false at h | | exact ytreeOK5 sound h w x y heq | | | | theorem master5 {N fy fz : Nat} | | h : allB leafZ5 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ5 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | EOF | | grep -n "sorry" Dev/Checker5.lean; echo ---; tail -5 /tmp/v5defs.log | | | | | | 153 --- TOOL bash --- | | saved head 7083 | | --- | | | | real 2m24.602s | | user 2m21.854s | | sys 0m1.973s | | | | | | 154 --- ASSISTANT --- | | V5Defs is still compiling, so I'll wait for that to finish before moving on to compile Checker5. While that's processing, I'm verifying the statement matching in xtreeOK5 sound to make sure the htree structure is correct after the simplification bridges, checking how the nested function calls and modulo operations compose together. | | | | I'm also catching an issue with how cond expressions reduce after rewriting—I need to explicitly apply cond true or cond false simp lemmas after the rewrite to actually simplify the conditional, not just rewrite the guard. And for the final step, the hypothesis hcov should match the core's expected form syntactically once fx is instantiated as f+1 , so I can pass it directly to xtree5 core without needing simpa . Simp with zeta-expansion will substitute the let-bound variables everywhere, which is fine. The modulo operation in xtreeOK5 correctly simplifies to 8 W + 1 % 225, and the nested newton calls reduce properly through multiplication. I removed an extra rewrite in the true branch and now need to verify the comp spec tactic arguments... | | | | Checking whether norm num; omega will work for the bound a < 0 + 2^8 — omega alone handles this when ha : a < 225 is in scope, but I'm concerned about sequencing: if norm num closes the goal, omega will fail on zero remaining goals. Actually, in Lean 4 running a tactic with no goals might just succeed silently rather than error. | | | | For the he -bound e < 0 + 2^12 , same logic applies. The trickier part is the leafX5 sound concern: after rewriting with leafX5 and then ← hedef , I need to verify that the rewrite actually works — Lean 4's rw accepts definition names like leafX5 if they're equational lemmas, and for non-recursive defs it uses the eq def form, which preserves the let-bindings as written in the definition. | | | | The issue is that rw leafX5 at h might leave h with unexpanded let-terms, blocking a subsequent rw ← hedef that tries to match inside the binder. The v4 code worked around this because simp only hc4 has zeta-expansion enabled by default, so the lets got expanded there. I should reorder my tactic: apply simp only first to zeta-expand, then do the rewrites. | | | | Actually, simp only leafX5 directly zeta-expands and unfolds the definition using its equational lemmas, so the let-bound expressions get substituted everywhere. Then rw ← hedef can replace all occurrences. I'll switch to that approach in both leafX5 sound and xtreeOK5 sound , using simp only with the relevant lemmas instead of plain rw . | | Let me fix the def-unfolding to use simp for zeta expansion of lets : | | bash | | | | cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/Checker5.lean' .read | | c=c.replace """ rw leafX5 at h | | rw ← hedef at h""",""" simp only leafX5 at h | | rw ← hedef at h""" | | c=c.replace """ rw xtreeOK5 at hh | | simp only add eqn, mul eqn, sub eqn, pow eqn, mod eqn at hh""",""" simp only xtreeOK5, add eqn, mul eqn, sub eqn, pow eqn, mod eqn at hh""" | | open 'Dev/Checker5.lean','w' .write c | | print 'ok' | | PYEOF | | sleep 120; tail -6 /tmp/v5defs.log | | | | | | 154 --- TOOL bash --- | | ok | | sys 0m1.973s | | Killed | | | | real 1m28.757s | | user 1m23.652s | | sys 0m4.743s | | | | | | 155 --- ASSISTANT --- | | The V5Defs compilation got killed after running for about 90 seconds, likely due to memory pressure even though the machine has plenty of free RAM — could be from earlier partest processes consuming resources. I'm trying to understand what decide +kernel actually does in this context — it seems to reduce the Decidable instance through the kernel, but constructing the actual proof term requires something more. | | | | The kernel's weak-head-normal-form evaluation might be creating massive expression closures that blow up memory. The whnf cache could be the culprit — with a million leaves each caching multiple expressions, that could easily consume several gigabytes. I should check the cgroup memory limit and run the compilation again with memory monitoring to see what's actually happening. | | bash | | | | cat /sys/fs/cgroup/memory.max /sys/fs/cgroup/memory.peak 2 /dev/null; dmesg 2 /dev/null | tail -5; free -g | head -2 | | | | | | 155 --- TOOL bash --- | | 10737418240 | | 10737418240 | | total used free shared buff/cache available | | Mem: 123 9 69 0 46 114 | | | | | | 156 --- ASSISTANT --- | | Looking at the memory breakdown, the cgroup limit is 10GB and we're hitting peak usage. The scan99b process is consuming around 7.5GB total—about 6.3GB resident memory plus roughly 2.8GB for S3 operations, with vector buffers across 16 threads accounting for about 4GB of that calculation. We're running tight on available memory. | | | | The real constraint is that Lean compilation needs another 2.5-3GB mostly from Mathlib imports and kernel work , which pushes us over the 10GB limit and triggers OOM. I'm weighing a few options: pausing scan99b during compilation is painful since both are long-running processes. Instead, I could reduce scan99b's memory footprint by adjusting the bucketing strategy—increasing LOGB from 22 to 25 would shrink the number of buckets from 1024 to 128, cutting the vector buffer size down to 512MB per thread 32MB each instead of 4GB total. This trades some cache efficiency during bucket flushes for a significant memory savings. Alternatively, dropping from 16 threads to 8 would halve the vector memory to 2GB, though that doubles the slowdown if we're CPU-bound—though we're already contended to about 4 cores effective anyway. | | | | The simplest path forward: set OMP NUM THREADS=8 and LOGB=25, which brings the total scan99b footprint down to about 3.6GB S3 at 2.8GB, bitsets at 0.5GB, vectors at 256MB , leaving 6.4GB headroom for Lean. I'll kill the current scan99b run, note the block where it stopped as a resume point, recompile with the new parameters, and restart from the last completed block boundary. First I need to check how many blocks scan99b has already processed to know where to resume. | | The cgroup memory limit of 10GB was exceeded by the scanner and Lean combined, so I'm restarting the scanner with smaller buffers to reduce memory usage. | | bash | | | | cat /tmp/scan99b.err; pkill -x scan99; sleep 1; sed -i 's/ define LOGB 22 / define LOGB 25 /' /tmp/scan99.c && grep -n "LOGB\|VCAP 65536" /tmp/scan99.c | head -3; gcc -O3 -march=native -fopenmp -o /tmp/scan99 /tmp/scan99.c -lm && echo compiled | | | | | | 156 --- TOOL bash --- | | |S3|=348144743 2.79 GB | | block 1/35 done marks=165241602558 zeros=0 | | 14: define LOGB 25 // members per bucket = 2^22 bitset 512KB | | 15: define VCAP 65536 // marks per vector | | 51: u64 nbuck= nb+ 1ULL<<LOGB -1 LOGB; | | compiled | | | | | | 157 --- ASSISTANT --- | | I'm working through the coverage calculation for scan99b, which only completed 1 out of 35 blocks, so I need to compute the new total by adding the partial coverage to the base amount and then scaling by the number of blocks processed. | | | | Now I'm recalculating the exact total in Python and planning to restart the scan with 10 threads and a log block size of 25, which gives me 128 buckets per thread at 32MB each—totaling 320MB across all threads. The S3 data structure for 2×10^13 entries needs about 2.79GB, plus 512MB for bit arrays, bringing the total memory requirement to roughly 3.7GB, which is manageable. | | bash | | | | python3 -c "print 86+99 14 2 32 "; cd /tmp && OMP NUM THREADS=10 nohup /tmp/scan99 $ python3 -c "print 86+99 14 2 32 " 20000000000000 /tmp/scan99c.out 2 /tmp/scan99c.err & sleep 3; head -2 /tmp/scan99c.err; ps -o pid,rss -p $ pgrep -x scan99 | | | | | | 157 --- TOOL bash --- | | 5952824672342 | | |S3|=348144743 2.79 GB | | PID RSS | | 8288 3574144 | | | | | | 158 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/V5Defs.lean -o devlib/V5Defs.olean"' /tmp/v5defs2.log 2 &1 & sleep 240; tail -4 /tmp/v5defs2.log; ps -o pid,rss,etime -C lean 2 /dev/null | tail -3 | | | | | | 158 --- TOOL bash --- | | | | real 2m40.085s | | user 0m56.097s | | sys 0m3.829s | | 4485 0 01:45:11 | | 5027 0 01:22:25 | | 7114 0 35:35 | | | | | | 159 --- ASSISTANT --- | | The V5Defs compilation finished in 2m40s, which seems fast, but the log only shows timing with no error messages—suggesting it succeeded. The user time was only 56 seconds, which is suspicious given that comp true should take around 90 seconds or more. Looking back at the earlier v5defs.log, there was a "Killed" message for V5Defs, so Blobs.olean must have already been built. The 2m40s wall time with just 56s user time means the kernel likely consumed about 40 seconds, which is plausible. | | | | My estimate was 80-90 seconds at 4.5 microseconds per step, though it could be faster. There are some stale Lean processes lingering with zero RSS—zombie-like remnants from killed partest runs—but I'll ignore those. Let me verify the olean file exists and check the full log for any errors. | | bash | | | | cat /tmp/v5defs2.log; ls -la /workspace/leanproject/devlib/; cd /workspace/leanproject && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker5.lean -o devlib/Checker5.olean"' /tmp/c5.log 2 &1 & echo compiling Checker5 | | | | | | 159 --- TOOL bash --- | | Killed | | | | real 2m40.085s | | user 0m56.097s | | sys 0m3.829s | | total 2184 | | drwxr-xr-x. 2 root root 46 Aug 2 22:25 . | | drwxr-xr-x. 1 root root 62 Aug 2 22:21 .. | | -rw-r--r--. 1 root root 305912 Aug 2 22:25 Blobs.olean | | -rw-r--r--. 1 root root 1926944 Aug 2 22:22 Checker.olean | | compiling Checker5 | | | | | | 160 --- ASSISTANT --- | | V5Defs is running out of memory again despite having 3.6GB allocated, and Lean's kernel is consuming over 6GB. The decide +kernel tactic on COMP is the culprit—the kernel's weak head normal form cache is exploding because each of the 225 classes generates 4096 expression trees, and every node and leaf creates cached entries plus closures, which balloons to roughly 1GB just from a million leaves with cached expressions, though it's clearly worse than that. I'm trying to understand how decide +kernel actually works and why the elaborator is causing this memory blowup. | | | | The kernel produces a term like of decide eq true Eq.refl true and then does a heavy definitional equality check to verify decide COMP = true , with the TypeChecker caching everything until completion. Checker5 will also get killed at the same point since it imports V5Defs.olean, which failed to build, so the import will fail with a missing olean file. I need to kill this and think through the options: either split COMP into eight smaller theorems so each decide +kernel gets its own kernel instance and the cache gets freed between chunks, or reduce the expression tree since a large fraction of the leaves are guards that could be restructured, or investigate what's actually consuming the memory—maybe it's not comp true itself but the elaboration of the V5Defs file or the olean serialization. | | | | I'm testing by compiling V5Defs without comp true to measure the baseline, then adding comp true back in chunks. I could also reduce kernel memory by running decide +kernel on smaller subtrees, like 16 chunks of 16 classes each. The plan is to restructure COMP as a conditional that branches on a threshold, define chunk theorems for each range, then combine them using the allB succ rewriting pattern that was validated in TestChunk—building a combiner tree that reduces 16 chunks down to 8, then 4, then 2, then 1. I need to normalize the address calculation and validate the chunk approach with a test, then figure out where the memory issue is coming from by adding an exit point before the problematic theorem and recompiling to isolate the culprit. | | V5Defs was OOM-killed again. Let me isolate whether comp true's decide is the memory hog, and split it into chunks. | | bash | | | | pkill -f "Checker5" ; cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/V5Defs.lean' .read | | c=c.replace """def COMP : Bool := allBH fun a = cond Nat.ble 225 a true compA a 8 0 | | | | set option maxHeartbeats 4000000 in | | theorem comp true : COMP = true := by decide +kernel | | ""","""def compG : Nat → Bool := fun a = cond Nat.ble 225 a true compA a | | | | def COMP : Bool := allB compG 8 0 | | """ | | open 'Dev/V5Defs.lean','w' .write c | | print c c.index 'def compG' :c.index 'end D' | | PYEOF | | | | | | 160 --- TOOL bash --- | | <stdout </stdout | | <stderr Terminated | | </stderr | | <returncode 143</returncode | | | | 161 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && grep -n "compG\|def COMP\|comp true" Dev/V5Defs.lean | | | | | | 161 --- TOOL bash --- | | 82:def COMP : Bool := allBH fun a = cond Nat.ble 225 a true compA a 8 0 | | 85:theorem comp true : COMP = true := by decide +kernel | | | | | | 162 --- ASSISTANT --- | | I ran into an issue where the pkill command matched my own bash process instead of the target process—that's a classic pkill pitfall. I need to redo the edit without using pkill in the same command chain. | | The pkill matched my own command, so I'll redo the edit. | | bash | | | | cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/V5Defs.lean' .read | | old="""def COMP : Bool := allBH fun a = cond Nat.ble 225 a true compA a 8 0 | | | | set option maxHeartbeats 4000000 in | | theorem comp true : COMP = true := by decide +kernel""" | | new="""def compG : Nat → Bool := fun a = cond Nat.ble 225 a true compA a | | | | def COMP : Bool := allB compG 8 0""" | | assert old in c | | c=c.replace old,new | | open 'Dev/V5Defs.lean','w' .write c | | print "edited" | | PYEOF | | cat Dev/V5Defs.lean.chunks <<'EOF' | | EOF | | python3 - <<'PYEOF' | | generate chunk theorems + combiner, appended to V5Defs before "end D" | | c=open 'Dev/V5Defs.lean' .read | | chunks= | | for k in range 16 : | | chunks.append f"set option maxHeartbeats 4000000 in\ntheorem compT {k} : allB compG 4 {16 k} = true := by decide +kernel" | | comb= | | level 5..8: L{f} {a} | | prev= 4,16 k for k in range 16 | | names={ 4,16 k :f"compT {k}" for k in range 16 } | | for f in range 5,9 : | | cur= | | for a in range 0,256,2 f : | | l=names f-1,a ; r=names f-1,a+2 f-1 | | nm=f"compL{f} {a}" | | names f,a =nm | | comb.append f"""theorem {nm} : allB compG {f} {a} = true := by | | rw show {f}:Nat = {f-1}+1 from rfl, allB succ, show {a}:Nat + 2^{f-1} = {a+2 f-1 } by norm num | | rw {l}, {r} | | rfl""" | | final=f"""theorem comp true : COMP = true := by | | rw COMP | | exact compL8 0""" | | body="\n\n".join chunks+comb+ final | | c=c.replace "end D", body+"\n\nend D" | | open 'Dev/V5Defs.lean','w' .write c | | print "appended", len chunks , len comb | | PYEOF | | | | | | 162 --- TOOL bash --- | | edited | | appended 16 15 | | | | | | 163 --- ASSISTANT --- | | I need to verify the exact signature of allB succ in Checker.lean and understand how TestChunk applies it, particularly around the address rewriting with the norm num tactic and how it interacts with the subsequent term transformation. | | bash | | | | cd /workspace/leanproject && sed -n '/theorem allB succ/,/^$/p' Dev/Checker.lean; sed -n 1,40p Dev/TestChunk.lean; rm -f Dev/V5Defs.lean.chunks | | | | | | 163 --- TOOL bash --- | | theorem allB succ p : Nat → Bool f a : Nat : | | allB p f+1 a = allB p f a .and allB p f a + 2^f := rfl | | | | import FormalConjectures.Util.ProblemImports | | set option linter.style.moduleDocstring false | | | | /- Kernel-friendly checker that a given N has no representation | | N = T w + C4 x + C6 y + C8 z | | where T w = w+2 w+1 /2, C4 x = x x+1 x+2 x+3 /24, | | C6 y = y⋯ y+5 /720, C8 z = z⋯ z+7 /40320. -/ | | | | namespace D | | | | /-- balanced bounded forall: allB p f a = true iff p i for all i ∈ a, a + 2^f . -/ | | def allB p : Nat → Bool : Nat → Nat → Bool := | | fun fuel = Nat.rec motive := fun = Nat → Bool | | p | | fun f ih a = ih a .and ih Nat.add a Nat.pow 2 f | | fuel | | | | theorem allB zero p : Nat → Bool a : Nat : allB p 0 a = p a := rfl | | | | theorem allB succ p : Nat → Bool f a : Nat : | | allB p f+1 a = allB p f a .and allB p f a + 2^f := rfl | | | | theorem allB sound {p : Nat → Bool} : ∀ f : Nat a : Nat , allB p f a = true → | | ∀ i, a ≤ i → i < a + 2^f → p i = true := by | | intro f | | induction f with | | | zero = | | intro a h i h1 h2 | | have : i = a := by omega | | simpa this using h | | | succ f ih = | | intro a h i h1 h2 | | rw allB succ, Bool.and eq true at h | | rcases Nat.lt or ge i a + 2^f with hlt | hge | | · exact ih a h.1 i h1 hlt | | · refine ih a + 2^f h.2 i hge ? | | have : a + 2^ f+1 = a + 2^f + 2^f := by | | rw Nat.pow succ ; omega | | omega | | | | | | | | 164 --- ASSISTANT --- | | The combiner pattern is working as expected. I need to update comp spec in Checker5 since the COMP definition changed from allBH sound to allB sound with compG — I'll apply allB sound with the appropriate arguments and unfold compG to derive that compG a = true . | | bash | | | | cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/Checker5.lean' .read | | old=""" have h := allBH sound 0 comp true a Nat.zero le by norm num; omega | | have hble : Nat.ble 225 a = false := by""" | | new=""" have h := allB sound 0 comp true a Nat.zero le by omega | | simp only compG at h | | have hble : Nat.ble 225 a = false := by""" | | assert old in c | | c=c.replace old,new | | open 'Dev/Checker5.lean','w' .write c | | print "ok" | | PYEOF | | nohup bash -c 'time lake env sh -c "LEAN PATH=$LEAN PATH:devlib lean Dev/V5Defs.lean -o devlib/V5Defs.olean"' /tmp/v5defs3.log 2 &1 & | | sleep 30; ps -o pid,rss,etime,args -C lean | grep V5Defs | head -2 | | | | | | 164 --- TOOL bash --- | | ok | | | | | | 165 --- ASSISTANT --- | | bash | | | | sleep 90; tail -3 /tmp/v5defs3.log; ps -o rss,etime -C lean 2 /dev/null | tail -2; grep -c . /tmp/v5defs3.log | | | | | | 165 --- TOOL bash --- | | real 0m1.289s | | user 0m0.483s | | sys 0m0.306s | | 0 01:25:50 | | 0 39:00 | | 7 | | | | | | 166 --- ASSISTANT --- | | bash | | | | head -10 /tmp/v5defs3.log | | | | | | 166 --- TOOL bash --- | | Dev/V5Defs.lean:1:0: error: unknown module prefix 'FormalConjectures' | | | | No directory 'FormalConjectures' or file 'FormalConjectures.olean' in the search path entries: | | | | devlib | | /root/.elan/toolchains/leanprover--lean4---v4.27.0/lib/lean | | | | real 0m1.289s | | user 0m0.483s | | sys 0m0.306s | | | | | | 167 --- ASSISTANT --- | | I see the issue with the variable expansion—I used double quotes around the bash command, which caused $LEAN PATH to expand too early before it was set. I need to switch to single quotes or properly escape the dollar sign so the variable gets evaluated at the right time. | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/V5Defs.lean -o devlib/V5Defs.olean"' /tmp/v5defs4.log 2 &1 & sleep 100; ps -o pid,rss,etime,pcpu -C lean|tail -2; tail -2 /tmp/v5defs4.log | | | | | | 167 --- TOOL bash --- | | 7114 0 40:49 2.3 | | 8648 8169072 01:38 33.7 | | | | | | 168 --- ASSISTANT --- | | I'm noticing the memory usage is getting critical—the lean process is at 8.1GB and scan99 is consuming another 3.5-3.6GB, which would push the total past the 10GB cgroup limit and trigger an OOM killer, yet the system is still running. I'm wondering if scan99's S3 operations might be counted separately in the memory accounting, or if there's something else going on with how the memory.max limit is being applied. | | | | Looking at the decide +kernel tactic more carefully—it's calling kernel-level reduction on the Decidable instance, which should reduce allB compG 4 0 = true through Bool.decEq and then kernel-reduce the allB computation. The memory footprint per chunk shouldn't be this large though. With 16 compA instances, each evaluating a 4096-leaf tree, and caching around 50 nodes per expression at roughly 100 bytes each, I'd expect maybe 300MB per chunk, not 8GB. Something's off—possibly the type inference cache is bloating things up as the kernel checks types on every reduced subterm. | | | | Or maybe the elaborator itself is the culprit. Even with decide +kernel , the elaborator still builds the Expr for the decide term before the kernel takes over. The environment might be accumulating state across all 16 chunk theorems instead of freeing caches per declaration like it should. | | | | Actually, wait — could the memory spike be from importing or elaborating something unrelated? The literals are fine at 0.3MB, but those exponential expressions in the bounds are suspicious. For the guard region where a ≥ 225, the short-circuit evaluation works correctly. And even for real values where f goes up to 11, computing 2^ 12·2048 gives a 24-kilobit number, which is manageable. The power expressions themselves shouldn't be the issue. | | | | But if it OOMs again, I should isolate a single chunk and watch the RSS to see what's actually consuming memory. The Mathlib import alone is 2.5-3GB, and if RSS is hitting 8GB, that's way more than just the library — the mapped .olean files could be adding another 2-4GB on top of that. The kernel work from previous chunks might be leaving residual memory too. Let me check how the memory usage evolves as chunks process. | | bash | | | | sleep 120; ps -o pid,rss,etime,pcpu -C lean|tail -1; tail -2 /tmp/v5defs4.log; cat /sys/fs/cgroup/memory.current | | | | | | 168 --- TOOL bash --- | | 8648 9042520 04:11 35.3 | | 7556636672 | | | | | | 169 --- ASSISTANT --- | | Watching the memory usage closely—RSS is showing 9GB but cgroup reports 7.56GB, which suggests some shared memory overcounting. The cgroup limit is 10GB total with current usage at 7.5GB, and CPU is sitting at 35% with contention. Both scan99 and lean are consuming significant memory, with scan99 at 3.6GB and lean around 3.9GB. I'll monitor until the process completes or gets killed, but if it does get terminated, I'll need to try pausing scan99 during compiles since SIGSTOP won't actually free up memory. | | | | The real challenge is that both scan99 and lean need memory simultaneously. I could reduce scan99's footprint by dropping threads to 4 or adjusting the NHI parameter to shrink the S3 cache from 2.8GB down to around 2.2GB, but that's marginal. A simpler approach would be to manually coordinate—kill scan99 during heavy lean compilation phases and restart it afterward, accepting the 9-15 minute loss per block boundary. It's painful but workable. I'm also wondering if the kernel itself is the memory bottleneck, or if decide +kernel is keeping both the elaborator and kernel caches in memory simultaneously. Making chunks smaller 32 chunks of 8 classes instead of 16 could halve the per-chunk memory footprint, but I need to figure out how much of that 3-4GB per chunk is actually the kernel cache at runtime. | | | | Wait—I'm realizing the final runtime theorems with 54M leaves could catastrophically OOM regardless of scan99. If the kernel's whnf cache grows unboundedly during a single decide call, that's a hard limit on how many leaves I can evaluate in one theorem. The v4 benchmarks ran fine, but I don't know what tree sizes were actually tested. I need to check what was benchmarked and whether large runs were attempted, then figure out if the kernel cache grows linearly with evaluated leaves and never evicts. If it does, I'm capped at maybe 5-10M leaves per 4GB, which means the final run would need to be split across 20-50 separate theorems instead of one monolithic proof. | | | | The chunking plan already handles this by generating per-z-chunk theorems, so I just need to tune chunk sizes to stay under 2-4M leaves each. But something's off—the current per-chunk memory for 16 classes is hitting 4-6GB even though 16 compA × 4096 only gives 65K leaves. That shouldn't take 4GB unless something pathological is happening, like each bsA leaf evaluation caching the full 2Mbit SELB shifts. | | | | Looking at the actual evaluation: the compA body creates a new instantiation per argument, and the whnf cache key treats each as distinct. For the e-tree with 4096 leaves, each leaf evaluation runs a condition check on bounded values, computes colFree via a small lookup table, and handles K1 shifts only 225 bits plus bsA shifts up to 24Kbit—so the memory footprint should be manageable if I'm not accidentally duplicating the shift data across evaluations. | | | | But the real problem emerges when I trace through the per-leaf caching: each Nat.rec unfold in the allB4 computation generates expressions that get cached at the whnf level. If each leaf produces around 100 cached expressions at roughly 150 bytes each, that's 15KB per leaf. Scaling that across 65K leaves per chunk gives 1GB, which is plausible—but for the full 54M leaves, that balloons to 810GB, which is completely infeasible unless I split the work into 200+ separate theorems with 4GB limits each. That would mean roughly 300 theorems, each handling around 270K leaves, which is theoretically possible but feels like an extreme fragmentation strategy. | | | | Before I spiral further into estimates, I should actually measure this. Let me wait for the current compile to finish, then run a controlled experiment measuring memory usage against leaf count—testing something like xtreeOK5 on a single large subtree of ~1000 leaves, and separately a y-subtree spanning 32 y-coordinates. I should also reconsider whether using Lean's native reduction would help, though native decide is off the table. There might be other ways to reduce the per-leaf memory footprint that I haven't explored yet. | | | | The whnf cache is keyed by expression pointer, and entries accumulate as we unfold Nat.rec—this is where the real overhead lives. The substituted lambda body for each leaf the leafX5 applied to its arguments creates a large term with hundreds of nodes including the sqTest2 chain, and while the constants themselves are just references, the whole expression still balloons to maybe 30KB per leaf. The cache prevents garbage collection of these expressions, which explains the memory scaling I'm seeing. I could potentially avoid caching altogether by creating a fresh TypeChecker object per leaf, but that might introduce other bottlenecks. | | | | The real solution is chunking: split the proof into many smaller theorems of 200-400K leaves each 2-4GB, 30-60 seconds to verify , then combine them. With N around 6-13 trillion leaves, that's 150-650 chunks total. The tricky part is aligning chunk boundaries to the allB subtree structure across the z,y space—the z-tree with fy=9 creates a y-tree inside each leafZ5 that's one whnf call, but when z is small like z=0 , the full y-range spans 500 y-values with ~1000 leaves each, which is 500K leaves or 5-8GB—way too big for a single theorem. | | | | So I need finer granularity: chunk at the y-subtree level instead, creating theorems for each z, y-range pair that prove allB over a 16-y chunk. The key insight is that I can't feed chunk results back into kernel evaluation—instead, I restructure the proof entirely: prove each per- z,y-range chunk lemma by decide separately, then combine them logically rather than through kernel evaluation. | | | | For a given z, if N is large enough relative to c8z, the branch is trivial via omega. Otherwise, for each y-range chunk, I only need to verify that allB holds over that interval. Then I assemble the full ytreeOK5 proof by applying allB sound to each chunk: for any y less than 2^fy, I locate which chunk contains it and use that chunk's proven result. | | | | At the ytree level, I combine the chunk lemmas using the allB succ pattern with boolean rewriting true.and true = true , which gives me ytreeOK5 as a theorem per z without re-evaluating the tree. Then I move upward to the z-level, but instead of defining leafZ5 as a boolean that would re-evaluate ytree internally, I use ytreeOK5 sound directly and restructure the master proof to avoid that redundant evaluation. | | | | For the final master theorem, I need to handle all z < 2^fz by cases: either N ≤ c8·z which I verify via decide/norm num on the literal value of c8·z , or I apply ytreeOK5 sound with the assembled facts that allB leafY5 N c8·z fy 0 = true and ble N c8·z + c6· 2^fy = true. Then I assemble the proof for all 256 values of z using interval cases. | | | | For the assembly itself, I'm considering whether to use interval cases with 256 branches or a cleaner approach: prove individual per-z theorems Zz for each literal z, then combine them in the final theorem using pattern matching on z with 150 branches since zmax ≈ 150 . The pattern-match approach generates a function that dispatches on each z literal and applies the corresponding pre-proved theorem, with a fallback case that uses c8 mono to show c8·z N for z ≥ zmax. For the y-dimension with fy=9, I have 512 y values to handle similarly. Assembling the chunk lemmas with normalization and rewriting tactics to verify the leaf condition holds, then generating the universal quantifier statement that excludes the boundary case. | | | | Now I'm estimating the total scale: with z values up to around 150 and roughly 20-32 chunks per z, that's potentially 3000-5000 theorems to prove, each taking 10-30 seconds, which balloons to 12+ hours of computation time—no real improvement over the previous approach despite the memory constraints being tighter. | | | | The per-theorem overhead is manageable since imports happen once per file and the kernel's decide tactic only takes milliseconds to start up, so the bottleneck is really the leaf-level computation time plus chunk assembly overhead. Memory-wise, each chunk needs to stay under 1.5GB to coexist with the scan99 process and Mathlib's base libraries within a 10GB budget, and since the kernel re-evaluates shared cbof extractions across chunks around 225 possible per class at roughly 30 microseconds each , that overhead is negligible. | | | | I'm setting the chunk size to around 100-200K based on a memory budget of 3GB for base, 2GB for chunks, and 3.6GB for scan99, which should fit within 10GB total. I need to wait for the current compile to finish and check if it's hitting memory limits—the RSS was already at 9GB after 4 minutes, so I'll measure the per-leaf memory precisely in the next benchmark run to finalize the chunk size. | | This reveals a key constraint: kernel whnf cache grows with leaves per theorem, so the final run must be chunked into many theorems. Let me check the current compile. | | bash | | | | sleep 60; tail -3 /tmp/v5defs4.log; ps -o pid,rss,etime,pcpu -C lean 2 /dev/null|tail -1; cat /sys/fs/cgroup/memory.current /sys/fs/cgroup/memory.peak | | | | | | 169 --- TOOL bash --- | | 8648 9767260 06:39 36.4 | | 8312586240 | | 10737418240 | | | | | | 170 --- ASSISTANT --- | | The memory usage is climbing steadily across chunks—RSS went from 8.1 to 9.7GB in just five minutes—which suggests the issue isn't a single chunk consuming that much, but rather memory not being freed between theorems. Caches or garbage collection might not be returning memory to the OS properly. The memory pattern will tell me whether the allocator is actually reclaiming between theorems or just accumulating — if it's sawtooth-shaped we're fine, but monotone growth means we're doomed anyway. At 6:39 elapsed with 35% CPU contention and roughly 60-100 seconds of actual kernel work, we might finish this run around the 5-minute mark plus elaboration overhead, so I should let it continue and see if we hit chunk 10+. If it dies, I can temporarily disable scan99 to free up resources and retry, but mimalloc may eventually decommit those freed pages anyway. | | bash | | | | sleep 90; tail -3 /tmp/v5defs4.log; ps -o pid,rss,etime -C lean 2 /dev/null|tail -1; tail -1 /tmp/scan99c.err; cat /sys/fs/cgroup/memory.current | | | | | | 170 --- TOOL bash --- | | 8648 10505328 08:31 | | |S3|=348144743 2.79 GB | | 9066029056 | | | | | | 171 --- ASSISTANT --- | | bash | | | | sleep 120; tail -3 /tmp/v5defs4.log; ps -o pid,rss -C lean 2 /dev/null|tail -1; cat /sys/fs/cgroup/memory.current | | | | | | 171 --- TOOL bash --- | | real 10m19.132s | | user 3m33.631s | | sys 0m7.238s | | 7114 0 | | 3719909376 | | | | | | 172 --- ASSISTANT --- | | The build finished in about 10 minutes with most of the time spent on contention and kernel work for the V5Defs compilation. Now I need to check the logs for any errors and verify that the olean files were generated successfully. | | bash | | | | head -20 /tmp/v5defs4.log; ls -la /workspace/leanproject/devlib/ | | | | | | 172 --- TOOL bash --- | | | | real 10m19.132s | | user 3m33.631s | | sys 0m7.238s | | total 2748 | | drwxr-xr-x. 2 root root 66 Aug 2 22:48 . | | drwxr-xr-x. 1 root root 62 Aug 2 22:21 .. | | -rw-r--r--. 1 root root 305912 Aug 2 22:25 Blobs.olean | | -rw-r--r--. 1 root root 1926944 Aug 2 22:22 Checker.olean | | -rw-r--r--. 1 root root 573696 Aug 2 22:48 V5Defs.olean | | | | | | 173 --- ASSISTANT --- | | V5Defs compiled successfully without errors. The completeness lemma for the blob is verified in the kernel. I'm noticing the memory behavior across the 16-class chunks—each chunk has around 65K leaves, and the total memory usage climbed to 10.5GB, which suggests either accumulation or that mimalloc isn't returning memory properly, though the system handled it fine overall. | | | | Estimating per-leaf memory: with each chunk containing roughly 65K leaves and about 10 probes per leaf heavier than runtime leaves , I'm getting around 500MB per chunk, or about 8KB per leaf. Now moving on to compile Checker5.lean, which should be quick since it's just proofs without heavy decision procedures. | | V5Defs compiled clean — the completeness lemma comp true is verified. Now compile Checker5 the soundness proofs : | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker5.lean -o devlib/Checker5.olean"' /tmp/c5b.log 2 &1 & sleep 150; cat /tmp/c5b.log | head -40 | | | | | | 173 --- TOOL bash --- | | Dev/Checker5.lean:200:51: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | t ≥ 0 | | s ≥ 0 | | 0 ≤ r ≤ 2699 | | p ≥ 0 | | p - q ≤ -1 | | p - u ≥ 0 | | 2700 o + r ≥ 0 | | n ≥ 0 | | n - o ≥ 1 | | 2700 n - 2700 o - r ≥ 1 | | m ≥ 0 | | m - 2700 o - r ≥ 0 | | l ≥ 0 | | j ≥ 0 | | h ≥ 0 | | g ≥ 0 | | g - h ≥ 0 | | c ≥ 0 | | c - j ≤ -1 | | c - l ≤ -1 | | -1 ≤ 8 c - 225 d ≤ 223 | | b ≥ 0 | | b - c ≤ -1 | | where | | b := ↑ c4 x | | c := ↑W | | d := ↑ 8 W + 1 / 225 | | g := ↑fx | | h := ↑ fla a | | j := ↑ c4 2700 2 ^ fx - f | | l := ↑ c4 xcap + 1 | | m := ↑ newton newton 24 W | | n := ↑2 ^ fx - f | | o := ↑x / 2700 | | p := ↑i | | q := ↑2 ^ fla a | | r := ↑ cbof a .shiftRight Nat.mul 12 i .land 4095 | | s := ↑ 2 ^ fx - f ↑ 2 ^ f | | | | | | 174 --- ASSISTANT --- | | I'm hitting a nonlinear arithmetic issue in the omega tactic—it can't handle the multiplication of k and 2^f as separate atoms when trying to prove the bound k 2^f + i < 0 + 2^fx, so I need to find a different approach to discharge this goal. I need to check the actual file around line 200 to see what's happening at that column position — the omega constraint list does include the variables from hklt and hpow, which suggests we're already inside the hjlt proof, and the goal of k+1 ≤ 2^ fx−f should be provable from the constraint that n − o ≥ 1 where n := 2^ fx−f and o is k, so the issue might be specifically with how that by omega call is structured at that location. | | bash | | | | cd /workspace/leanproject && sed -n 185,215p Dev/Checker5.lean; sed -n 40,44p /tmp/c5b.log | | | | | | 174 --- TOOL bash --- | | rw this | | exact hcf | | exact hnots 2 w+3 hv.symm | | | false = | | -- column has candidates: covered by the SEL enumeration | | have hbs := comp spec a ha e helt hcf | | obtain ⟨i, hi0, hilt, hslot⟩ := bsA sound hbs | | -- j = k 2^f + i is in the tree | | have hklt : k < 2 ^ fx - f := by omega | | have hjlt : k 2 ^ f + i < 2 ^ fx := by | | have hpow : 2:Nat ^ fx = 2 ^ fx - f 2 ^ f := by | | rw ← Nat.pow add | | congr 1 | | omega | | simp only pow eqn at hilt | | calc k 2 ^ f + i < k 2 ^ f + 2 ^ f := by omega | | = k + 1 2 ^ f := by ring | | ≤ 2 ^ fx - f 2 ^ f := Nat.mul le mul right by omega | | = 2 ^ fx := hpow.symm | | have hilt2 : i < 2 ^ f := by simpa only pow eqn using hilt | | have hleaf := allBH sound 0 htree k 2 ^ f + i Nat.zero le by omega | | -- decode | | have hdec1 : Nat.land k 2 ^ f + i 2 ^ f - 1 = i := by | | show k 2 ^ f + i &&& 2 ^ f - 1 = i | | rw Nat.and two pow sub one eq mod, Nat.mul comm k, Nat.mul add mod, | | Nat.mod eq of lt hilt2 | | have hdec2 : Nat.shiftRight k 2 ^ f + i f = k := by | | rw Nat.shiftRight eq div pow, Nat.mul comm k, Nat.mul add div Nat.two pow pos f , | | Nat.div eq of lt hilt2 | | omega | | have hedef : e = Nat.land Nat.shiftRight cbof a Nat.mul 12 | | s := ↑ 2 ^ fx - f ↑ 2 ^ f | | t := ↑k ↑ 2 ^ f | | u := ↑2 ^ f | | Dev/Checker5.lean:212:10: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | ?m ?n | | | | | | 175 --- ASSISTANT --- | | I'm looking at a Lean proof where I need to apply Nat.mul le mul right to establish that ≤ 2 ^ fx - f 2 ^ f . The issue is that the function signature in recent Mathlib expects both the inequality proof and the multiplier as explicit arguments, so I need to adjust how I'm passing the arguments to match the updated API. I should try using gcongr with omega to handle the congruence closure reasoning — by gcongr <; omega should let gcongr reduce the goal to k+1 ≤ 2^ fx-f and then omega can discharge it, avoiding the issue where omega was trying to prove the full multiplicative goal directly. | | | | For the second error around line 212, the lemma Nat.and two pow sub one eq mod seems to be stated differently than expected — the error about pattern ?m ?n suggests the actual lemma might involve a right shift operation rather than the form I'm trying to rewrite with, so I need to check the exact statement in this version of Mathlib. | | bash | | | | cd /workspace/leanproject && cat /tmp/t3.lean <<'EOF' | | import Mathlib | | check @Nat.and two pow sub one eq mod | | open Nat in | | example k f i : Nat h : i < 2^f hk : k+1 ≤ 2^ f+3-f : k+1 2 ^ f ≤ 2^ f+3-f 2 ^ f := | | Nat.mul le mul hk le rfl | | example j f : Nat : j &&& 2^f-1 = j % 2^f := by | | simpa using Nat.and two pow sub one eq mod j f | | EOF | | timeout 280 lake env lean /tmp/t3.lean 2 &1 | head -10 | | | | | | 175 --- TOOL bash --- | | Nat.and two pow sub one eq mod : ∀ x n : ℕ , x &&& 2 ^ n - 1 = x % 2 ^ n | | /tmp/t3.lean:4:23: warning: unused variable h | | | | Note: This linter can be disabled with set option linter.unusedVariables false | | /tmp/t3.lean:7:2: warning: try 'simp' instead of 'simpa' | | | | Note: This linter can be disabled with set option linter.unnecessarySimpa false | | | | | | 176 --- ASSISTANT --- | | I'm checking the precedence of the bitwise AND operator with subtraction in this lemma — since &&& binds looser than - , the expression x &&& 2 ^ n - 1 correctly parses as x &&& 2^n − 1 . The rewrite tactic failed on a pattern match, likely because the second element in the rewrite list didn't match the expected form ?m ?n . | | | | Looking at the actual lemma Nat.shiftRight eq div pow : m n = m / 2 ^ n , I see the issue — the goal contains Nat.shiftRight spelled out explicitly rather than using the operator syntax, so the rewrite can't find the pattern. I need to add a show statement to convert k 2 ^ f + i f = k into the right syntactic form before applying the rewrite. Similarly, for the earlier step with the bitwise AND, I should verify the show statement is already in place. I also need to add a calc step with Nat.mul le mul to handle the multiplication inequality, and then check if there are additional errors beyond these two fixes. | | bash | | | | grep -n "error" /tmp/c5b.log | head; cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/Checker5.lean' .read | | c=c.replace " ≤ 2 ^ fx - f 2 ^ f := Nat.mul le mul right by omega ", | | " ≤ 2 ^ fx - f 2 ^ f := Nat.mul le mul by omega le rfl" | | c=c.replace """ have hdec2 : Nat.shiftRight k 2 ^ f + i f = k := by | | rw Nat.shiftRight eq div pow,""",""" have hdec2 : Nat.shiftRight k 2 ^ f + i f = k := by | | show k 2 ^ f + i f = k | | rw Nat.shiftRight eq div pow,""" | | open 'Dev/Checker5.lean','w' .write c | | print "ok" | | PYEOF | | | | | | 176 --- TOOL bash --- | | 1:Dev/Checker5.lean:200:51: error: omega could not prove the goal: | | 43:Dev/Checker5.lean:212:10: error: Tactic rewrite failed: Did not find an occurrence of the pattern | | 82:Dev/Checker5.lean:232:32: error: omega could not prove the goal: | | 99:Dev/Checker5.lean:235:32: error: omega could not prove the goal: | | ok | | | | | | 177 --- ASSISTANT --- | | bash | | | | sed -n 82,130p /tmp/c5b.log; cd /workspace/leanproject && sed -n 225,240p Dev/Checker5.lean | | | | | | 177 --- TOOL bash --- | | Dev/Checker5.lean:232:32: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | e ≥ 0 | | d ≥ 0 | | d - e ≥ 1 | | c ≥ 0 | | b ≥ 0 | | b - c ≤ -1 | | a ≥ 0 | | a - b ≥ 1 | | where | | a := ↑ c4 | | 2700 2 ^ bif true then fla 8 W + 1 % 225 + 1 else fla 8 W + 1 % 225 - fla 8 W + 1 % 225 | | b := ↑W | | c := ↑ c4 newton newton 24 W + 1 | | d := ↑ fla 8 W + 1 % 225 | | e := ↑ bif true then fla 8 W + 1 % 225 + 1 else fla 8 W + 1 % 225 | | Dev/Checker5.lean:235:32: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | e ≥ 0 | | d ≥ 0 | | d - e ≥ 1 | | c ≥ 0 | | b ≥ 0 | | b - c ≤ -1 | | a ≥ 0 | | a - b ≥ 1 | | where | | a := ↑ c4 | | 2700 2 ^ bif false then fla 8 W + 1 % 225 + 1 else fla 8 W + 1 % 225 - fla 8 W + 1 % 225 | | b := ↑W | | c := ↑ c4 newton newton 24 W + 1 | | d := ↑ fla 8 W + 1 % 225 | | e := ↑ bif false then fla 8 W + 1 % 225 + 1 else fla 8 W + 1 % 225 | | | | real 0m28.491s | | user 0m9.461s | | sys 0m2.282s | | have hh : xtreeOK5 W = true := h | | simp only xtreeOK5, add eqn, mul eqn, sub eqn, pow eqn, mod eqn at hh | | rw Bool.and eq true, Bool.and eq true at hh | | obtain ⟨htree, hcov, hcap⟩ := hh | | rw Nat.blt eq at hcov hcap | | cases hc : Nat.ble c4 2700 W with | | | true = | | rw hc at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap | | | false = | | rw hc at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap | | | | /- y and z levels -/ | | | | def leafY5 N r8 y : Nat : Bool := | | | | | | 178 --- ASSISTANT --- | | After applying the rewrite with rw hc at htree hcov , the conditional expression isn't fully reduced because the simplifier needs explicit rules for the true and false branches. I need to add simp only cond true to handle the true case and cond false for the false case, which will let the simplifier properly reduce the conditional and give htree and hcov the correct form of fx. The omega tactic can't handle unreduced conditionals, so this simplification step is essential before it can verify the inequality. | | | | For the proof structure itself, I'm handling both branches of the conditional: in the true branch, fx becomes f+1, and in the false branch, fx stays as fla. The key is making sure the core lemma receives the right instantiation of fx in each case — when I pass hcov to xtree5 core , it needs to match the exact form the lemma expects, which is why I'm using plain hcov rather than trying to simplify it further with simpa . | | bash | | | | cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/Checker5.lean' .read | | old=""" cases hc : Nat.ble c4 2700 W with | | | true = | | rw hc at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap | | | false = | | rw hc at htree hcov | | exact xtree5 core htree by omega by simpa using hcov hcap""" | | new=""" cases hc : Nat.ble c4 2700 W with | | | true = | | rw hc at htree hcov | | simp only cond true at htree hcov | | exact xtree5 core htree by omega hcov hcap | | | false = | | rw hc at htree hcov | | simp only cond false at htree hcov | | exact xtree5 core htree Nat.le refl hcov hcap""" | | assert old in c | | c=c.replace old,new | | open 'Dev/Checker5.lean','w' .write c | | print "ok" | | PYEOF | | nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker5.lean -o devlib/Checker5.olean"' /tmp/c5c.log 2 &1 & sleep 100; grep -n error /tmp/c5c.log | head; tail -3 /tmp/c5c.log | | | | | | 178 --- TOOL bash --- | | ok | | 1:Dev/Checker5.lean:200:51: error: omega could not prove the goal: | | real 0m28.265s | | user 0m9.598s | | sys 0m2.068s | | | | | | 179 --- ASSISTANT --- | | bash | | | | sed -n 1,45p /tmp/c5c.log | | | | | | 179 --- TOOL bash --- | | Dev/Checker5.lean:200:51: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | t ≥ 0 | | s ≥ 0 | | 0 ≤ r ≤ 2699 | | p ≥ 0 | | p - q ≤ -1 | | p - u ≥ 0 | | 2700 o + r ≥ 0 | | n ≥ 0 | | n - o ≥ 1 | | 2700 n - 2700 o - r ≥ 1 | | m ≥ 0 | | m - 2700 o - r ≥ 0 | | l ≥ 0 | | j ≥ 0 | | h ≥ 0 | | g ≥ 0 | | g - h ≥ 0 | | c ≥ 0 | | c - j ≤ -1 | | c - l ≤ -1 | | -1 ≤ 8 c - 225 d ≤ 223 | | b ≥ 0 | | b - c ≤ -1 | | where | | b := ↑ c4 x | | c := ↑W | | d := ↑ 8 W + 1 / 225 | | g := ↑fx | | h := ↑ fla a | | j := ↑ c4 2700 2 ^ fx - f | | l := ↑ c4 xcap + 1 | | m := ↑ newton newton 24 W | | n := ↑2 ^ fx - f | | o := ↑x / 2700 | | p := ↑i | | q := ↑2 ^ fla a | | r := ↑ cbof a .shiftRight Nat.mul 12 i .land 4095 | | s := ↑ 2 ^ fx - f ↑ 2 ^ f | | t := ↑k ↑ 2 ^ f | | u := ↑2 ^ f | | | | real 0m28.265s | | user 0m9.598s | | | | | | 180 --- ASSISTANT --- | | I'm trying to figure out what's at line 200, column 51 after my edit—whether it's the calc step with the omega tactic or something else. Let me check the surrounding lines to understand the context, particularly looking at the constraints and what the hilt hypothesis contains after the simplification step. ve rewritten the goal and hypotheses at the time set executes, but hilt comes later from comp spec / bsA sound applied to a , which produces a result with fla a in it — so even though set f := fla a creates a local definition, subsequent terms mentioning fla a don't automatically fold to f . This leaves hilt : i < Nat.pow 2 fla a , and after simplifying with pow eqn it becomes i < 2 ^ fla a , but omega needs to connect this to the let-binding f := fla a through hfdef . | | | | The issue is that omega treats f and fla a as separate atoms — it has the constraint fla a ≤ fx which uses fla a := h , but it's missing the constraint f = fla a that would link them. The real problem is the negated goal: when omega negates k 2^f + i < k 2^f + 2^f , it gets i ≥ 2^f , which becomes p - u ≥ 0 in its internal representation, but omega only has i < 2^ fla a available, not i < 2^f . The fix is to establish hilt2 before the calc block so omega has the right constraint in scope. Continuing with the proof structure... I'm tracking how omega is connecting the remainder variable r with the modulo expression x % 2700, and verifying that the constraints involving r like 2700 o + r ≥ 0 and m − 2700 o − r ≥ 0 are properly satisfied through the substitution, even though the variable was introduced through a set declaration. | | bash | | | | cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/Checker5.lean' .read | | old=""" obtain ⟨i, hi0, hilt, hslot⟩ := bsA sound hbs | | -- j = k 2^f + i is in the tree | | have hklt : k < 2 ^ fx - f := by omega | | have hjlt : k 2 ^ f + i < 2 ^ fx := by | | have hpow : 2:Nat ^ fx = 2 ^ fx - f 2 ^ f := by | | rw ← Nat.pow add | | congr 1 | | omega | | simp only pow eqn at hilt | | calc k 2 ^ f + i < k 2 ^ f + 2 ^ f := by omega | | = k + 1 2 ^ f := by ring | | ≤ 2 ^ fx - f 2 ^ f := Nat.mul le mul by omega le rfl | | = 2 ^ fx := hpow.symm | | have hilt2 : i < 2 ^ f := by simpa only pow eqn using hilt""" | | new=""" obtain ⟨i, hi0, hilt, hslot⟩ := bsA sound hbs | | -- j = k 2^f + i is in the tree | | have hilt2 : i < 2 ^ f := by | | rw hfdef | | simpa only pow eqn using hilt | | have hklt : k < 2 ^ fx - f := by omega | | have hjlt : k 2 ^ f + i < 2 ^ fx := by | | have hpow : 2:Nat ^ fx = 2 ^ fx - f 2 ^ f := by | | rw ← Nat.pow add | | congr 1 | | omega | | calc k 2 ^ f + i < k 2 ^ f + 2 ^ f := by omega | | = k + 1 2 ^ f := by ring | | ≤ 2 ^ fx - f 2 ^ f := Nat.mul le mul by omega le rfl | | = 2 ^ fx := hpow.symm""" | | assert old in c | | c=c.replace old,new | | open 'Dev/Checker5.lean','w' .write c | | print "ok" | | PYEOF | | nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker5.lean -o devlib/Checker5.olean"' /tmp/c5d.log 2 &1 & sleep 90; grep -n error /tmp/c5d.log|head; tail -2 /tmp/c5d.log | | | | | | 180 --- TOOL bash --- | | ok | | user 0m10.275s | | sys 0m2.011s | | | | | | 181 --- ASSISTANT --- | | bash | | | | grep -n "error" /tmp/c5d.log | head -5; sed -n 1,50p /tmp/c5d.log | | | | | | 181 --- TOOL bash --- | | | | real 0m21.330s | | user 0m10.275s | | sys 0m2.011s | | | | | | 182 --- ASSISTANT --- | | I'm noticing the log only shows timing metrics without errors, which is odd given the earlier failures took longer. Let me verify the olean file was actually written and check if the error grep comes back empty—that would confirm this run succeeded despite the suspicious early completion. | | bash | | | | ls -la /workspace/leanproject/devlib/Checker5.olean && echo SUCCESS | | | | | | 182 --- TOOL bash --- | | -rw-r--r--. 1 root root 1155488 Aug 2 22:55 /workspace/leanproject/devlib/Checker5.olean | | SUCCESS | | | | | | 183 --- ASSISTANT --- | | Checker5 is now fully compiled and verified. I need to validate the entire pipeline end-to-end by running test cases through master5 — starting with a simple theorem like the v4 test, then checking against actual values where the checker can confirm zero representations exist. | | | | For benchmarking, I'm measuring kernel time and memory usage per leaf across realistic tree chunks, testing around 20 different W values to understand performance characteristics and determine optimal chunk sizes. I'm also tracking an allB operation on a leafY5 chunk to get concrete metrics. | | | | For the benchmark file, I'm selecting test pairs where xtreeOK5 returns true — these are W values with no w,x solutions to the equation. Most large random W values should pass since the density of T+C4 sums across the range is relatively sparse, so I'm calculating the coverage fraction to estimate how many pairs will succeed versus fail. | | | | Writing benchmark theorems that verify xtreeOK5 for specific W values using the decide tactic with kernel support, then timing the file and counting leaves via simulation to establish baseline performance. | | The v5 pipeline compiles successfully. Now I'll benchmark kernel time and memory per leaf with realistic W values, starting by verifying the candidates work in the simulator. | | bash | | | | cd /tmp && python3 - <<'EOF' | | import sim5, sim | | from sim import S | | Ws= | | w=5527622910037 | | import random | | random.seed 1 | | cands= 5527622910037 - k 987654321 - random.randint 0,10 6 for k in range 30 | | for W in cands: | | s0=S.xleaf | | ok=sim5.xtreeOK5 W | | if ok: Ws.append W,S.xleaf-s0 | | if len Ws =12: break | | tot=sum l for ,l in Ws | | print len Ws ,"good W, total jleaves",tot | | for W,l in Ws: print W,l | | EOF | | | | | | 183 --- TOOL bash --- | | 12 good W, total jleaves 13572 | | 5527622769146 2048 | | 5526634658863 256 | | 5525646712797 1024 | | 5524659105839 2 | | 5523671491878 1024 | | 5522684572260 4096 | | 5521696716652 512 | | 5520709206144 2 | | 5519721155968 512 | | 5518733223222 1024 | | 5517745895502 1024 | | 5516758217321 2048 | | | | | | 184 --- ASSISTANT --- | | I'm looking at the distribution of tree sizes across the test classes—each one has 2^ f+1 leaves, with one particular case having just 2 leaves. There are 12 test cases total with 13,572 leaves to verify. I need to benchmark these in Lean by running 12 theorems that check xtreeOK5 returns true for each case, measuring both user time and memory usage while accounting for baseline overhead from just the imports. | | | | I'm also noticing that the pairs with tiny trees 2 leaves correspond to the L=0 classes, which makes sense since L=0 gives f=0 and thus 2 leaves. This is promising for performance since real data tends to have many low-L classes, meaning most pairs will be small and fast to process. | | | | After the xtree benchmark, I'll also run a y-chunk test using allB with leafY5 on real data, which will give a more realistic picture of pair-level overhead since leafY5 computes W internally. | | bash | | | | cd /workspace/leanproject && { echo 'import Checker5'; echo 'set option maxHeartbeats 10000000'; echo 'namespace D'; python3 -c " | | ws= 5527622769146,5526634658863,5525646712797,5524659105839,5523671491878,5522684572260,5521696716652,5520709206144,5519721155968,5518733223222,5517745895502,5516758217321 | | for i,w in enumerate ws : print f'theorem bxt {i} : xtreeOK5 {w} = true := by decide +kernel' "; echo 'end D'; } Dev/BenchX.lean && cat /tmp/benchbase.lean <<'EOF' | | import Checker5 | | EOF | | nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean /tmp/benchbase.lean" ; echo BASE DONE; /usr/bin/time -v lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/BenchX.lean" ' /tmp/bx.log 2 &1 & sleep 150; cat /tmp/bx.log | grep -E "real|user|BASE|error|Maximum resident|Elapsed" | | | | | | 184 --- TOOL bash --- | | real 0m7.942s | | user 0m5.182s | | BASE DONE | | | | | | 185 --- ASSISTANT --- | | bash | | | | sleep 60; grep -E "real|user|BASE|error|Maximum resident|Elapsed" /tmp/bx.log; tail -3 /tmp/bx.log | | | | | | 185 --- TOOL bash --- | | real 0m7.942s | | user 0m5.182s | | BASE DONE | | sys 0m1.716s | | BASE DONE | | bash: line 1: /usr/bin/time: No such file or directory | | | | | | 186 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/BenchX.lean"' /tmp/bx2.log 2 &1 & | | sleep 5; PID=$ pgrep -f "lean Dev/BenchX" ; echo pid $PID; for i in $ seq 1 20 ; do sleep 10; ps -o rss= -p $PID 2 /dev/null || break; done | tail -5; grep -E "real|user|error" /tmp/bx2.log | | | | | | 186 --- TOOL bash --- | | pid 9241 9242 9245 9247 9248 9294 9295 | | 3152 | | 1452 | | 3152 | | 1452 | | 3152 | | real 0m20.825s | | user 0m7.384s | | | | | | 187 --- ASSISTANT --- | | The pgrep command picked up multiple processes, so the benchmark results are a bit noisy. The actual run took about 20.8 seconds, with a user time delta of roughly 2.2 seconds across 13,572 leaves—that's around 162 microseconds per leaf, which is actually slower than the previous version's 110 microseconds. The base implementation's user time includes imports taking about 5.2 seconds, and the new version has the same imports plus elaboration work for 12 theorems, so the kernel time difference of 2.2 seconds accounts for that extra overhead. | | | | Looking at the leaf distribution, most of them do full work including the sqTest2 operation since they fall within the xcap range, so 162 microseconds per leaf seems reasonable given the workload. Scaling this up to the full problem size of 5.5e12 would give an estimated kernel-user time around 5300 seconds or about 88 minutes, which translates to 2.5 to 4 hours wall time depending on CPU contention. The memory measurements got confused because pgrep matched multiple processes, so I need a better approach to track memory usage accurately. | | | | Rather than trying to measure with fake data, I should generate chunk theorems for a real subset that simulation verified as passing—something like z=5 with y-chunks covering a range minus the known failing spots—sized to match the real problem's scale. This would let me calibrate the actual runtime and memory footprint without needing a complete counterexample. | | | | For the test run, I'm thinking z=100 for a larger memory footprint with moderate W, and z=0 where W approaches N itself. A few 16-y chunks at z=0 would give me around 16-32K leaves per chunk, which is substantial enough to measure. But first I need to check the simulation to see which y-chunks actually pass at N=5527622910037 with z=0—all 16 y-values have to succeed for the chunk to work. | | Let me calibrate with realistic y-chunk theorems. First find passing y-chunks in the simulator: | | bash | | | | cd /tmp && python3 - <<'EOF' | | import sim5 | | from sim import S, c8 | | N=5527622910037 | | z=0; r8=c8 z | | find 2 consecutive 16-y chunks that fully pass, starting y=0 | | good= | | y=0 | | while len good <3 and y<512: | | s0=S.xleaf | | ok=all sim5.leafY5 N,r8,yy for yy in range y,y+16 | | if ok: good.append y,S.xleaf-s0 | | y+=16 | | print good | | EOF | | | | | | 187 --- TOOL bash --- | | 0, 28164 , 16, 23044 , 32, 26630 | | | | | | 188 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && cat Dev/BenchY.lean <<'EOF' | | import Checker5 | | set option maxHeartbeats 40000000 | | namespace D | | theorem by0 : allB leafY5 5527622910037 0 4 0 = true := by decide +kernel | | theorem by1 : allB leafY5 5527622910037 0 4 16 = true := by decide +kernel | | theorem by2 : allB leafY5 5527622910037 0 4 32 = true := by decide +kernel | | end D | | EOF | | nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/BenchY.lean"' /tmp/by.log 2 &1 & | | sleep 3; PID=$ pgrep -fx "lean Dev/BenchY.lean" || pgrep -f "BenchY" ; echo $PID; MAX=0; while kill -0 $ echo $PID|awk '{print $NF}' 2 /dev/null; do R=$ ps -o rss= -p $ echo $PID|awk '{print $NF}' 2 /dev/null||echo 0 ; "$R" -gt "$MAX" && MAX=$R; sleep 2; done; echo maxRSS $MAX; grep -E "real|user|error" /tmp/by.log | | | | | | 188 --- TOOL bash --- | | 9436 | | maxRSS 7231248 | | real 1m0.204s | | user 0m17.079s | | | | | | 189 --- ASSISTANT --- | | Looking at the BenchY results across three chunks totaling about 78K leaves, the per-leaf latency is holding steady around 153 microseconds. But the memory usage is alarming—maxRSS hit 7.23GB for what should be manageable data, suggesting roughly 60KB per leaf when accounting for the base import overhead. That's significantly higher than expected. | | | | The pattern suggests memory isn't being reclaimed between theorems within a single file. If each chunk uses around 1.6GB and they're accumulating rather than being freed, that would explain the 7.1GB total matching the observed maxRSS. This is catastrophic for the full 54M-leaf file scenario, which would theoretically require 3TB. The issue might be that Lean 4.27 keeps environment checking asynchronous—addDecl could be spawning kernel checks that retain intermediate state rather than freeing it immediately after completion. So I should isolate by0 and measure its peak memory usage alone, then add by1 and compare — that'll show whether memory accumulates across theorems or if each one independently consumes that much. | | Memory behavior is critical. Let me isolate: one chunk vs two chunks. | | bash | | | | cd /workspace/leanproject && head -4 Dev/BenchY.lean Dev/BenchY1.lean && grep "by0" Dev/BenchY.lean Dev/BenchY1.lean && echo "end D" Dev/BenchY1.lean && head -4 Dev/BenchY.lean Dev/BenchY2.lean && grep -E "by0|by1" Dev/BenchY.lean Dev/BenchY2.lean && echo "end D" Dev/BenchY2.lean | | for f in BenchY1 BenchY2; do | | nohup bash -c "time lake env sh -c \"LEAN PATH=\\\$LEAN PATH:devlib lean Dev/$f.lean\"" /tmp/$f.log 2 &1 & | | sleep 3; PID=$ pgrep -f "lean Dev/$f.lean" | tail -1 ; MAX=0; while kill -0 $PID 2 /dev/null; do R=$ ps -o rss= -p $PID 2 /dev/null||echo 0 ; "$R" -gt "$MAX" && MAX=$R; sleep 2; done; echo "$f maxRSS $MAX"; grep -E "real|user|error" /tmp/$f.log; done | | | | | | 189 --- TOOL bash --- | | BenchY1 maxRSS 6852820 | | Dev/BenchY1.lean:5:8: error: D.by0 has already been declared | | real 0m33.921s | | user 0m9.686s | | BenchY2 maxRSS 6956572 | | Dev/BenchY2.lean:5:8: error: D.by0 has already been declared | | real 0m28.178s | | user 0m12.567s | | | | | | 190 --- ASSISTANT --- | | I'm noticing an issue with how the file was being processed—the head command grabbed the first four lines including the theorem declaration, then grep added it again, creating a duplicate. Interestingly, BenchY1 still executed the first instance once, but the second declaration failed with an "already declared" error that appeared after elaboration had started. | | | | Looking at the timing: BenchY1's user time of 9.7s matches roughly 5.2s base plus two runs of the 2.2s decide operation, and the memory peaked at 6.85GB. BenchY2 with three declarations by0, by0, by1 took 12.6s user time with three decide operations and similar peak memory around 6.96GB. | | | | This suggests a single by0 with 28K leaves uses somewhere around 2-4GB without strong accumulation, so I should run a clean test with just one by0 declaration and a minimal file to establish the baseline memory usage. | | bash | | | | cd /workspace/leanproject && printf 'import Checker5\nset option maxHeartbeats 40000000\n' Dev/BY1.lean && printf 'theorem q1 : D.allB D.leafY5 5527622910037 0 4 0 = true := by decide +kernel\n' Dev/BY1.lean && printf 'import Checker5\n' Dev/BY0.lean && printf 'theorem q0 : D.xtreeOK5 5524659105839 = true := by decide +kernel\n' Dev/BY0.lean | | for f in BY0 BY1; do | | nohup bash -c "time lake env sh -c \"LEAN PATH=\\\$LEAN PATH:devlib lean Dev/$f.lean\"" /tmp/$f.log 2 &1 & | | sleep 3; PID=$ pgrep -f "lean Dev/$f.lean" | tail -1 ; MAX=0; while kill -0 $PID 2 /dev/null; do R=$ ps -o rss= -p $PID 2 /dev/null||echo 0 ; "$R" -gt "$MAX" && MAX=$R; sleep 2; done; echo "$f maxRSS $MAX"; grep -E "real|user|error" /tmp/$f.log; done | | | | | | 190 --- TOOL bash --- | | BY0 maxRSS 6359540 | | real 0m20.341s | | user 0m5.113s | | BY1 maxRSS 809992 | | real 0m32.836s | | user 0m9.866s | | | | | | 191 --- ASSISTANT --- | | The memory measurements are throwing me off — BY0 with just two leaves is showing 6.36GB maxRSS while BY1 with 28K leaves only uses 810MB, which doesn't make sense. I think pgrep is catching the wrong process in the lake wrapper chain, possibly matching the shell or lake itself rather than the actual Lean process, which would explain why the numbers are so unreliable. | | | | I should try a more robust approach using cgroup memory.peak instead, which tracks the actual peak memory usage — though it's currently saturated at 10.7GB. I can reset it by writing to the memory.peak file supported in kernel 6.7+ , or I could measure VmHWM directly from /proc/PID/status for the exact Lean binary process. The tricky part is getting the right PID reliably and capturing the final memory value before the process exits, so I'll need to poll /proc/$PID/status periodically and keep the last recorded value. | | My measurement harness is picking wrong PIDs. Redo carefully with VmHWM polling of the actual lean binary: | | bash | | | | cd /workspace/leanproject && cat /tmp/measure.sh <<'EOF' | | /bin/bash | | f=$1 | | nohup bash -c "time lake env sh -c \"LEAN PATH=\\\$LEAN PATH:devlib lean $f\"" /tmp/m.log 2 &1 & | | sleep 4 | | PID=$ ps -C lean -o pid=,etime= | sort -k2 | head -1 | awk '{print $1}' | | LAST=0 | | while -d /proc/$PID ; do | | V=$ grep VmHWM /proc/$PID/status 2 /dev/null | awk '{print $2}' | | -n "$V" && LAST=$V | | sleep 1 | | done | | echo "$f VmHWM ${LAST} kB" | | grep -E "real|user|error" /tmp/m.log | | EOF | | chmod +x /tmp/measure.sh | | /tmp/measure.sh Dev/BY0.lean; /tmp/measure.sh Dev/BY1.lean | | | | | | 191 --- TOOL bash --- | | Dev/BY0.lean VmHWM 6359616 kB | | real 0m8.427s | | user 0m4.937s | | Dev/BY1.lean VmHWM 6843380 kB | | real 0m25.781s | | user 0m9.623s | | | | | | 192 --- ASSISTANT --- | | Looking at the memory profiling results, the trivial case with just two leaves is consuming 6.36GB, which is surprisingly high. The issue isn't coming from the leaves themselves—it's the transitive imports pulling in Checker and Mathlib that's driving the memory usage up to around 6.3GB just for the import overhead. | | | | When I add 28K leaves, memory only increases to 6.84GB, meaning each leaf is accumulating roughly 17KB. This accumulation pattern holds across the benchmarks: the baseline import sits at 6.3GB, and additional theorems pile on incrementally without being freed between them. The math checks out—28K leaves at 17KB each adds about 480MB to the baseline, matching the observed jump. But this raises a critical problem: if 54 million leaves each consume 17KB and memory doesn't get freed, that's 918GB total, which is impossible in a single Lean process unless memory is being reclaimed somehow. | | | | To figure out whether memory is truly leaking or just reusable, I'd run a test file with 10 copies of the same chunk at different y-ranges. If peak memory hits baseline plus 10 times the delta, that's accumulation. If it stays around baseline plus one delta, memory is being reused. The answer matters enormously: if it's accumulating, a 10GB verifier can only handle about 215K leaves before running out of space—nowhere near the 54 million needed. | | | | But wait, there's another possibility. What if async elaboration in Lean 4.27 is keeping kernel checks queued in memory? The CLI might have async elaboration enabled by default, meaning checks could be running lazily or in parallel, holding onto memory even though they're serialized on a single thread. I should disable async elaboration and rerun the benchmark to see if that changes the peak memory profile. | | Baseline import alone is ~6.3GB and leaf memory may be accumulating across theorems. Let me test if disabling async elaboration changes memory retention: | | bash | | | | cd /workspace/leanproject && cat /tmp/measure2.sh <<'EOF' | | /bin/bash | | f=$1; opt=$2 | | nohup bash -c "time lake env sh -c \"LEAN PATH=\\\$LEAN PATH:devlib lean $opt $f\"" /tmp/m2.log 2 &1 & | | sleep 4 | | PID=$ ps -C lean -o pid=,etime= | sort -k2 | head -1 | awk '{print $1}' | | LAST=0 | | while -d /proc/$PID ; do | | V=$ grep VmHWM /proc/$PID/status 2 /dev/null | awk '{print $2}' | | -n "$V" && LAST=$V | | sleep 1 | | done | | echo "$f $opt VmHWM ${LAST} kB" | | grep -E "real|user|error" /tmp/m2.log | | EOF | | chmod +x /tmp/measure2.sh | | /tmp/measure2.sh Dev/BenchY.lean "-DElab.async=false"; /tmp/measure2.sh /tmp/benchbase.lean "" | | | | | | 192 --- TOOL bash --- | | Dev/BenchY.lean -DElab.async=false VmHWM 6840720 kB | | real 0m56.609s | | user 0m17.146s | | /tmp/benchbase.lean VmHWM 6371196 kB | | real 0m18.969s | | user 0m5.281s | | | | | | 193 --- ASSISTANT --- | | Looking at the memory benchmarks for the async=false case with BenchY across 3 chunks totaling 78K leaves, the peak memory is 6.84GB compared to the baseline 6.37GB, which works out to about 6KB per leaf. I'm noticing something odd though—the single-chunk case BY1 also shows 6.84GB peak, which matches the 3-chunk async=false result, so I need to recalculate the baseline numbers to clarify what's actually happening with the memory overhead. | | | | The key insight is that with async=false, memory gets reused across theorems rather than accumulating, so the peak stays at base + max-single-theorem instead of scaling linearly. With async enabled the default , BenchY hit 7.23GB, which is roughly base + 2× overhead due to concurrent task retention. For the final verification run, I should keep chunks under 60K leaves to stay around 7.4GB peak, but I need to account for scan99's memory footprint too—if both are running, that's 6.4 + 1 + 3.6 = 11GB, which exceeds the 10GB limit, so I'll need to stop scan99 during the final run. | | | | The challenge is that the verifier will compile Spec.lean with its own settings, so I can't pass -DElab.async=false as a command-line flag. But I can set it directly in the file using set option Elab.async false at the top, which should activate the memory reuse mode. I'm not entirely certain about the verifier's memory requirements yet though. The overhead is negligible across 1100-2600 chunks, but kernel time remains the bottleneck at ~90 minutes for large N values — acceptable but risky. I could optimize leaf operations to maybe 120μs instead of 150μs, but that's marginal, so I'm moving on to the generator. Now I need to finalize the Spec.lean structure and verify whether disabling async elaboration affects Mathlib imports. | | | | For the actual implementation, I'm organizing the file with the license header, imports, the A306477 definition, then a namespace containing the checker and verification definitions, followed by the blob data, chunk assembly, chunk theorems for the real N values, and finally the assembly and disproof. The chunk assembly strategy varies y-chunk sizes based on z-levels to keep leaves under ~50K — at N=5.5e12 with small z values, a y-chunk of 16 gives about 25K leaves, which fits the constraint. | | | | With fyc=4 giving 32 chunks per z across roughly 150 z-levels, I'm looking at around 4800 chunks plus combiners, totaling maybe 10K theorems. The elaboration overhead of 10K theorems at ~50ms each comes to about 500 seconds, which is acceptable. I could optimize further with adaptive fyc values, targeting 30-50K leaves per chunk — that would give roughly 1350 chunks total, which is more manageable. I'll go with the adaptive approach and then handle the per-z assembly. | | | | For the assembly step, I need to ensure chunks align at power-of-2 boundaries, which standard binary segmentation handles naturally. The key insight is that ytreeOK5 sound works for any r8 value, so I can set r8 to the literal L z expression. Then the final per-z conclusion becomes t2w + c4x + c6y + c8 z ≠ N, and I'll rewrite c8 z = L z using a norm num lemma. | | | | For proving the c8 definition equals L z on literals, I'm checking whether norm num can handle Nat.div on concrete values, or if I should use decide with kernel computation instead. Since Nat operations are natively compiled in the elaborator with GMP backing, either rfl or norm num should work fine for reducing Nat.div on literal arguments. | | | | Now I'm thinking about structuring the chunk theorems directly with c8-expressions rather than extracting literals first. The key insight is that I can state ytreeOK5 N fy c8 z = true and prove it by decide, since the kernel will evaluate c8 z cheaply per leaf. Then I construct ytreeOK5 by combining the allB check with a bounds check using ble, and apply ytreeOK5 sound to assemble everything into the final tree shape. I should refactor this by creating a general ytree5 parts sound lemma that captures the proof structure, then apply it to each z case. For the master assembly, I'll handle z < ZMAX through case analysis and z ≥ ZMAX by showing the bound exceeds N, then close with omega. | | | | For the implementation, I'm considering whether to match directly on 150 literal cases followed by a pattern for n+150, which would create deep Nat.casesOn chains during elaboration—potentially slow but workable. Alternatively, I could use a binary tree structure over z values to keep the matching more efficient, though that adds complexity. | | | | The cleaner approach seems to be using interval cases to handle all 150 cases at once, then providing the corresponding proofs for each case. This might be heavy for elaboration with 150 trivial goals, but it's a one-time cost and more maintainable than manual match generation. For larger z values where the leaf count stays under the 50K budget, I can use the leafZ5-based chunking approach with assembly via allB, but for smaller z values that would exceed memory, I need to derive the leafZ5 result from sub-chunks instead of evaluating the entire tree directly in the kernel. Building the y-assembly proofs by rewriting with successor rules and reflexivity to establish the full range up to the target bound, then combining all chunks into the master proof structure. Continuing the proof by rewriting the goal after applying Ez and cond false, which leaves me needing to show ytreeOK5 N 9 c8 z equals true. I'm expanding ytreeOK5's definition and verifying that both Az and Bz hold, which should close the goal by reflexivity. For the case where z is large, I need to handle this separately. | | | | For larger z values above the split threshold, I'm using a decision procedure on the range chunks to establish that the allB property holds at the leaf level, then combining the left and right subtrees through the allB succ tree structure to prove the overall property. The key insight is that for z values where N ≤ c8 z roughly z 150 at N = 5.5e12 , these fall into the big-z range where the kernel can quickly evaluate the leaf condition as true, making the entire top range a single efficient chunk. | | | | Now I'm computing the exact threshold where c8 z = C z+7,8 exceeds N—checking that C 150,8 ≈ 9.3e12 and C 160,8 ≈ 1.55e13 pins zN between 143 and 165, so the structure handles this uniformly. The elaboration cost breaks down to roughly 1350 decide-chunks plus rewrite-based proofs for the Lz components, totaling around 5000 small theorems that each take 10-50ms to elaborate, giving a total of 100-250 seconds plus about 90 minutes of kernel work. | | | | For the final proof, I'm setting fy = 9 with 512 y-values to cover N < 2.4e13, and fz = 8 with 256 z-values to handle N ≤ C 263,8 ≈ 4.66e14. The top-level theorem uses master5 to verify that leafZ5 N 9 returns true for all 8 z-values, then applies the constraint that N ≤ c8 2^8 by decision procedure. From there, A eq zero takes the universal property that no combination of coefficients sums to N and produces the final disproof. | | | | For chunk-size adaptivity, I'm computing leaf counts per z and y-block using a fast estimator, then selecting the y-chunk size fy ∈ {2..9} that maximizes coverage while staying under ~40K leaves and ~800MB memory. The chunking strategy walks y in aligned blocks and uses recursive segment-tree logic: if the estimated leaf count fits the cap or we're at a base case, emit a decide-chunk; otherwise split and recurse on halves, then combine results. | | | | Now I need to verify that once the final N is found, every chunk evaluates to true, and I'll run the generator with chunking enabled to assert this. I should also test file-level async elaboration settings for quick validation, then run an end-to-end assembly test on a small case to ensure everything works before the final run—though finding a good test case is tricky since I need either a real near-miss or a different predicate entirely to avoid false chunks. | | | | Testing with N=0 makes all leaf conditions instantly true, which validates the assembly mechanics but doesn't exercise the Ez path since all z's take the r8-true branch, changing the proof shape. With N=1, the z=0 case has r8=0, so ble 1 0 fails, pushing into the ytree path where leafY5 also fails, then xtreeOK5 1 finds a solution but the chunk still fails. Moving to N=2 with W=2, I'm checking whether t2w=1 and working through the c4x calculation. | | | | The real problem is that every N≥1 appears to have a representation the conjecture holds up to 1e10 , so the Ez/Lz path can only be tested on W-values that actually pass, but a full z=0 ytree test requires all y to pass—which is impossible for covered N. Since an end-to-end all-true test is impossible without a real counterexample, I'm pivoting to test the mechanics on a modified predicate instead, using a leafY5 variant where sqTest2 is replaced with a function that always returns true, then running the full generator pipeline with a fake flag enabled. Writing the generator... | | I'm verifying that the Elab.async false option works in-file and checking the scan progress. | | bash | | | | cd /workspace/leanproject && cat /tmp/opt.lean <<'EOF' | | set option Elab.async false | | theorem tt : 1 + 1 = 2 := rfl | | EOF | | lake env lean /tmp/opt.lean && echo OPT OK; tail -2 /tmp/scan99c.err; date | | | | | | 193 --- TOOL bash --- | | OPT OK | | block 1/34 done marks=168544021750 zeros=0 | | block 2/34 done marks=167977771304 zeros=0 | | Sun Aug 2 23:13:48 UTC 2026 | | | | | | 194 --- ASSISTANT --- | | I've got the async compilation setting working at the file level, and the scan is progressing through blocks—currently around 6.8e12 with no zeros found yet, though the lean compilation is slowing things down a bit. Now I need to write the full generator script that takes the counterexample and paths as inputs and produces the complete Spec.lean file, starting with the original license header. | | | | The final Spec.lean will include the A306477 definition exactly as it appears now without the sorry theorem , then the full namespace D content pulled from Checker.lean—all the core lemmas and definitions like allB, the notation bridges, maskBit, sqAll, newton, sqTest2, and the choose equations that feed into A eq zero, making sure to reference the real A306477 definition from above rather than a local copy. For Checker5, I need to include the core multiplication and period logic, the tree validation functions with their soundness proofs, and master5. I'm refactoring ytreeOK5 sound to take h1 and h2 as separate arguments, keeping leafZ5 and its soundness proof as-is since they're used by the kernel-evaluated chunks for large z values, and I'll need to handle the leafZ5 build lemma with its per-z generated tactic scripts. | | | | For the generated part per N, the generator will emit y-chunk theorems with kernel evaluation and maxHeartbeats set to 0 at the file level, y-assembly theorems using rewriting, Ez/Bz/Lz theorems for each small-z value, big-z range chunks that assemble to allB, the top-level htop and master5 theorems leading to hall, and the base case hzero proving A306477 N0 equals zero. | | | | Now I'm setting up the disproof of the conjecture by introducing the hypothesis and deriving a contradiction from the base case. The assembly theorems follow a systematic naming scheme based on z, f, and a parameters, with straightforward generation despite the large number of theorems. For the y-level combine step, I'm building allB-based theorems that merge results from the f-level at positions a and a+2^f. | | | | Proving the successor case... Now I'm working through the strategy for handling mixed levels in the zsplit boundary: chunks need to be aligned at big-z-safe boundaries, so the generator checks each aligned block to see if it fits within the leaf capacity—if so, it emits a single decide-based proof, otherwise it recurses down; for level 0 with small z, it falls back to the Lz-style proof which requires additional y-chunking. | | | | The key constraint is that each decide chunk can handle roughly 40K leaves before hitting memory or time limits, and there are two critical pieces to verify: the top-level allB proof for the blocks themselves, and the per-small-z Bz inequality proof, both of which are cheap to compute. | | | | Now I'm working through the assembly at the y-level, where I need to establish that the leaf structure satisfies the required property, being careful about how c8 evaluates as an expression within the kernel during leaf computation. For the Lz case, I'm simplifying the leaf definition and then using the Ez proof to handle the false branch of the conditional. Now I'm setting up the master5 application with the assembled root node, verifying that the leaf structure and bounds check both hold by kernel decision. Then I need to handle A eq zero by checking its statement in Checker.lean and adapting it to reference the real A306477 sequence — removing the local definition and adjusting the generator to use the global one instead. | | | | I should review the original Spec.lean content to preserve the exact text. | | I'm reviewing the original Spec.lean and the A eq zero definition in Checker.lean to compare them. | | bash | | | | cd /workspace/leanproject && cat Submission/Spec.lean; echo =====; sed -n '/^def A306477/,/^theorem test0/p' Dev/Checker.lean | head -60 | | | | | | 194 --- TOOL bash --- | | import FormalConjectures.Util.ProblemImports | | | | open Nat Finset | | | | /-- | | A306477: Number of ways to write $n$ as $\binom{w+2}{2} + \binom{x+3}{4} + \binom{y+5}{6} + \binom{z+7}{8}$ | | with $w,x,y,z$ nonnegative integers, where $\binom{m}{k}$ denotes the binomial coefficient $\frac{m }{k m-k }$. | | -/ | | def A306477 n : ℕ : ℕ := | | let R := Finset.range n + 1 | | R.sum fun w = | | R.sum fun x = | | R.sum fun y = | | R.sum fun z = | | if w + 2 .choose 2 + x + 3 .choose 4 + y + 5 .choose 6 + z + 7 .choose 8 = n then 1 else 0 | | | | | | | | | | | | /-- | | Conjecture: a n 0 for all n 0. In other words, any positive integer n can be written as | | C w,2 + C x,4 + C y,6 + C z,8 , where w,x,y,z are integers greater than one. | | This is also known as "the 2-4-6-8 conjecture". | | -/ | | theorem oeis 306477 conjecture 1 : ∀ n : ℕ, 0 < n → 0 < A306477 n := by | | sorry | | ===== | | def A306477 n : ℕ : ℕ := | | let R := Finset.range n + 1 | | R.sum fun w = | | R.sum fun x = | | R.sum fun y = | | R.sum fun z = | | if w + 2 .choose 2 + x + 3 .choose 4 + y + 5 .choose 6 + z + 7 .choose 8 = n then 1 else 0 | | | | | | | | | | | | namespace D | | | | theorem A eq zero {N : Nat} hN : ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N : | | A306477 N = 0 := by | | simp only A306477 | | apply Finset.sum eq zero; intro w | | apply Finset.sum eq zero; intro x | | apply Finset.sum eq zero; intro y | | apply Finset.sum eq zero; intro z | | rw if neg | | rw choose2 eq, choose4 eq, choose6 eq, choose8 eq | | exact hN w x y z | | | | -- end-to-end plumbing validation on N = 0 | | theorem test0 : A306477 0 = 0 := | | | | | | 195 --- ASSISTANT --- | | The Checker.lean definition matches perfectly and the original Spec.lean file has no license header, so I'll keep that structure and just replace the sorry block with the disproof. Now I'm writing the generator script that reads the component files. | | | | The generator will build a static framework by combining the necessary parts from Checker.lean, V5Defs.lean with blob literals, and Checker5.lean, then move the A eq zero definition and choose bridges into it to reference the top-level A306477. It'll generate chunk and assembly theorems for a given N0 using recursive emitters with a simulation-based leaf-count estimator and validity checking. For testing the mechanics, I can generate for a small N like 23343989 where chunks containing the witness will fail compilation, letting me validate the structure while only the genuinely-false decide chunks produce errors. | | | | I also need to build an independent C verifier for candidate N0 that does a direct exhaustive check without the v5 machinery—just looping through z, y, x triples to verify the 8 N−s +1 odd-square condition. For the framework text assembly, instead of manually copying, I'll extract the needed declaration blocks from the Dev files programmatically by parsing top-level definitions and keeping a whitelist of what's actually needed from Checker.lean. | | | | Now I'm listing out all the specific declarations I need to pull in: the monotonicity lemmas for c4, c6, c8, the arithmetic equation lemmas, the square-testing functions like sqAll and newton, the bracket validation, the K-series constants and their related lemmas, and the alternative formulations like c4 alt and the choose coefficient equations. | | | | I need to verify that c4 mono, c6 mono, and c8 mono actually exist and trace their dependencies, along with eight t2, t2 ge one, and choose2 eq, plus any standard Nat lemmas from Mathlib that xtree5 proofs rely on. The safest approach is to extract the top-level definitions and theorems from the three Dev files in order, filter out the blacklisted items from v1-v4 that are already in Checker.lean like Q1-Q3, M1-M3, and the old sqTest, then keep everything else. | | | | Now I'm building an extraction script that parses the files by splitting on definition and theorem boundaries, handling set option directives and documentation comments that attach to the following declaration. | | | | I need to manage namespaces carefully — stripping them from the extracted units and wrapping everything in a single namespace D, while keeping A306477 as a top-level definition outside the namespace since it appears before the namespace reopens in the original file. The blob definitions from Blobs.lean stay inside the namespace, and I'll preserve the original file order when assembling the final output: Checker units first, then Blobs, then V5Defs, then Checker5, respecting all dependencies. I'm also setting the heartbeat limit to 2. | | | | For the heartbeat configuration, I'm debating whether to set maxHeartbeats to 0 globally or keep it high — the earlier code needed 1000000 for the sqAllK decides, and BenchY ran with 40000000, so I'll stick with a high value to avoid timeouts during elaboration and kernel steps. | | | | I'm also keeping Elab.async set to false for memory efficiency, and I'll leave the linter options as-is since warnings are acceptable for the submission. The final theorem will be named oeis 306477 conjecture 1.disproof . | | | | Writing the proof statement... | | | | Now I need to set up the extraction and verification pipeline — writing a script to generate the counterexample data and a standalone C verifier to check it independently. I'm also thinking through the chunking strategy: with leaves around 17KB each and a target total size under 800MB, that gives roughly 47,000 leaves to work with, each taking about 7 seconds to process. The capacity estimates suggest around 40,000 leaves based on the branching factor, so I need to make sure my estimator aligns with that. | | | | For validation, I'm deciding between trusting the fast estimator for chunk sizing versus running exact simulations for verification — the full Python simulation would take too long around 100 minutes for 54 million leaf calls , so I'll use the estimator for sizing but still need exact truth per chunk to confirm no solutions exist and validate structural coverage. | | | | The key insight is that chunks can only fail if a real solution exists ruled out by C verification , coverage checks fail which the estimator validates through exact Python arithmetic without enumerating leaves , or there are global issues already verified. So I can validate each pair quickly with Python assertions on the coverage bounds, then spot-check with random full leaf-level simulations for sanity. | | | | But there's a subtle failure mode: if a value turns out to be a perfect square for some enumerated x, that means a solution exists — but only if the root is odd and at least 3. When v equals 1, the boundary case handles it correctly. The Newton method needs to reliably bracket and converge to the floor of the square root, which is standard, but if the bracketing fails or Newton doesn't converge properly, I could get spurious false results for chunks. | | | | The Newton iteration with integer division converges monotonically to floor sqrt v — it's deterministic and quadratically fast, needing only about 10 iterations for 64-bit values. Since the simulation replicates this exactly, the only way to be completely certain is to run the exact x-loop for each pair, iterating only over the relevant slots like the kernel does. | | | | Running this in Python across all 55K pairs with ~700 slot evaluations each gives roughly 39M total evaluations, which takes 30-60 minutes on a single core. I'll parallelize this across 16 cores using multiprocessing to bring it down to about 4 minutes, then run it during the validation phase. | | | | Now I'm writing the generator and need to check TestChunk's exact working pattern to replicate it faithfully. | | I'll check the validated TestChunk combiner pattern before writing the generator. | | bash | | | | cd /workspace/leanproject && sed -n 40,80p Dev/TestChunk.lean | | | | | | 195 --- TOOL bash --- | | | | /- arithmetic pieces -/ | | | | def t2 w : Nat : Nat := Nat.div Nat.mul Nat.add w 2 Nat.add w 1 2 | | def p4 x : Nat : Nat := Nat.mul Nat.mul Nat.mul x Nat.add x 1 Nat.add x 2 Nat.add x 3 | | def c4 x : Nat : Nat := Nat.div p4 x 24 | | def p6 y : Nat : Nat := | | Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul y Nat.add y 1 Nat.add y 2 Nat.add y 3 Nat.add y 4 Nat.add y 5 | | def c6 y : Nat : Nat := Nat.div p6 y 720 | | def p8 z : Nat : Nat := | | Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul Nat.mul z Nat.add z 1 Nat.add z 2 Nat.add z 3 Nat.add z 4 Nat.add z 5 Nat.add z 6 Nat.add z 7 | | def c8 z : Nat : Nat := Nat.div p8 z 40320 | | | | theorem t2 def w : Nat : t2 w = w+2 w+1 /2 := rfl | | theorem p4 def x : Nat : p4 x = x x+1 x+2 x+3 := rfl | | theorem c4 def x : Nat : c4 x = p4 x / 24 := rfl | | theorem p6 def y : Nat : p6 y = y y+1 y+2 y+3 y+4 y+5 := rfl | | theorem c6 def y : Nat : c6 y = p6 y / 720 := rfl | | theorem p8 def z : Nat : p8 z = z z+1 z+2 z+3 z+4 z+5 z+6 z+7 := rfl | | theorem c8 def z : Nat : c8 z = p8 z / 40320 := rfl | | | | theorem t2 ge one w : Nat : 1 ≤ t2 w := by | | rw t2 def | | have h : 2 ≤ w+2 w+1 := by nlinarith | | omega | | | | theorem eight t2 w : Nat : 8 t2 w + 1 = 2 w+3 2 w+3 := by | | have h2 : 2 ∣ w+2 w+1 := by | | rcases Nat.even or odd w with he | ho | | · obtain ⟨k, hk⟩ := he | | exact ⟨ k+1 w+1 , by subst hk; ring⟩ | | · obtain ⟨k, hk⟩ := ho | | exact ⟨ w+2 k+1 , by subst hk; ring⟩ | | obtain ⟨k, hk⟩ := h2 | | have ht : t2 w = k := by rw t2 def, hk ; omega | | rw ht | | nlinarith hk | | | | theorem c4 mono {x x' : Nat} h : x ≤ x' : c4 x ≤ c4 x' := by | | rw c4 def, c4 def | | apply Nat.div le div right | | | | | | 196 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && grep -n "theorem tc\|rw \ show\|allB succ\|rfl" Dev/TestChunk.lean | sed -n 1,25p; sed -n '/tc0/,$p' Dev/TestChunk.lean | head -40 | | | | | | 196 --- TOOL bash --- | | 18:theorem allB zero p : Nat → Bool a : Nat : allB p 0 a = p a := rfl | | 20:theorem allB succ p : Nat → Bool f a : Nat : | | 21: allB p f+1 a = allB p f a .and allB p f a + 2^f := rfl | | 33: rw allB succ, Bool.and eq true at h | | 53:theorem t2 def w : Nat : t2 w = w+2 w+1 /2 := rfl | | 54:theorem p4 def x : Nat : p4 x = x x+1 x+2 x+3 := rfl | | 55:theorem c4 def x : Nat : c4 x = p4 x / 24 := rfl | | 56:theorem p6 def y : Nat : p6 y = y y+1 y+2 y+3 y+4 y+5 := rfl | | 57:theorem c6 def y : Nat : c6 y = p6 y / 720 := rfl | | 58:theorem p8 def z : Nat : p8 z = z z+1 z+2 z+3 z+4 z+5 z+6 z+7 := rfl | | 59:theorem c8 def z : Nat : c8 z = p8 z / 40320 := rfl | | 147:theorem mul eqn a b : Nat : Nat.mul a b = a b := rfl | | 148:theorem add eqn a b : Nat : Nat.add a b = a + b := rfl | | 149:theorem sub eqn a b : Nat : Nat.sub a b = a - b := rfl | | 150:theorem div eqn a b : Nat : Nat.div a b = a / b := rfl | | 151:theorem mod eqn a b : Nat : Nat.mod a b = a % b := rfl | | 152:theorem pow eqn a b : Nat : Nat.pow a b = a ^ b := rfl | | 226: exact sqTest sound h 2 w+3 rfl | | 421: rw show x + 1 + 3 = x + 3 + 1 from by omega, Nat.choose succ succ' x+3 3 | | 427: rw show x + 1 + 3 = x + 3 + 1 from by omega, Nat.choose succ succ' x+3 2 | | 433: rw show x + 1 + 3 = x + 3 + 1 from by omega, Nat.choose succ succ' x+3 1, | | 450: rw show xrun f+1 = fun v e3 e2 e1 = | | 454: true from rfl at hrun | | 457: rcases Nat.eq or lt of le hx with rfl | hlt | | 510: refine xrun sound 6000 0 by simp show c4 0 = 0 from rfl ? w x Nat.zero le x | | theorem tc0 : allB trivZ 2 0 = true := by decide +kernel | | theorem tc1 : allB trivZ 2 4 = true := by decide +kernel | | theorem tc2 : allB trivZ 2 8 = true := by decide +kernel | | theorem tc3 : allB trivZ 2 12 = true := by decide +kernel | | | | theorem tc01 : allB trivZ 3 0 = true := by | | rw show 3:Nat = 2+1 from rfl, allB succ | | rw show 0:Nat + 2^2 = 4 by norm num | | rw tc0, tc1 | | rfl | | theorem tc23 : allB trivZ 3 8 = true := by | | rw show 3:Nat = 2+1 from rfl, allB succ | | rw show 8:Nat + 2^2 = 12 by norm num | | rw tc2, tc3 | | rfl | | theorem tcAll : allB trivZ 4 0 = true := by | | rw show 4:Nat = 3+1 from rfl, allB succ | | rw show 0:Nat + 2^3 = 8 by norm num | | rw tc01, tc23 | | rfl | | end D | | | | | | 197 --- ASSISTANT --- | | Now I'm planning the generator script that takes a count parameter and optional output path and leaf cap, then loads the pickled blobs and metadata before parsing the Lean files to extract declaration units with whitelist/blacklist filtering. | | | | The estimator will compute leaf counts per pair using the metadata, applying a formula based on whether the weight is below a threshold, then emit the recursive z-structure with validation assertions and optional simulation checking before outputting the final Spec.lean file. | | | | For parsing, I'm using a line-based scanner to identify declaration boundaries by looking for keywords like def, theorem, and documentation markers, extracting names from tokens following those keywords, and attaching preceding documentation and options to their declarations. | | | | Now I'm building the whitelist for Checker.lean, starting with the core functions and lemmas like allB, t2, p4, c4 and their variants, along with the montonicity proofs and helper functions like maskBit and sqAll, then continuing with the Newton-related functions, equation handlers, test constants, and the choose lemmas, while blacklisting everything else in the file. I need to generate the final theorems and check dependencies carefully—looking for any names referenced in the kept declarations that might be missing, like allB sound. I'll emit the structure for each N value, computing the exact leaf count per coordinate pair, then generate theorem names that prove the allB property holds for each leafY5 instance with the appropriate flags and offsets. I'm refining the rewrite strategy for the theorem generation—consolidating the rewrite list into a single ordered sequence allB succ first, then address normalization, then substitutions while keeping the lines separate as they've been validated. For the emitZ function, I'm estimating the total size by summing over all z values in the range where c8 z stays below N, accounting for pairs and per-leaf overhead, then deciding whether to emit a decide-based theorem or recurse further if f equals zero. Proving that A306477 at the specific value equals zero, then using that to establish a contradiction showing the conjecture is false. I need to make sure the rewrite in the proof matches the literal form in the hypothesis, and there's a note about checking the leafY5 argument structure with the kernel. | | | | Now I'm working through how the z-literal gets evaluated at each leaf node, with partial application and caching ensuring the same pointer is reused across multiple applications. The naming scheme keeps things compact for the file size, and there are around five thousand theorem names in the rewrite references. | | | | For the big z-chunks, the memory estimate needs to account for both the leaf count and the overall capacity limit of about seventeen kilobytes. The pair overhead involves a cached computation per distinct expression occurrence, so each leaf builds its own tree structure with the computation evaluated fresh per pair, which takes roughly fifty microseconds and is negligible. I'm also checking edge cases like using literals directly in the function application, and verifying that the boolean inequality proofs hold through kernel computation. | | | | Now for the estimator itself: I'm iterating through all 256 possible z values, computing the first component and checking if it exceeds the capacity. If not, I loop through 512 y values to find where the combined estimate crosses the threshold, then determine whether we need a single leaf or multiple pairs. I'm precomputing all these decisions into lookup arrays indexed by z, y pairs—that's 131,000 entries total, which stays fast. For validation, I'm running an exact Python simulation across all pairs using multiprocessing to parallelize over z values. I should also add some Lean options to the generated file to disable async elaboration and increase the heartbeat limit for longer computations. | | | | Regarding the decide +kernel tactic: I'm uncertain whether the heartbeat limit applies to kernel reduction inside decide. From past experience with similar proofs, maxHeartbeats 1000000 was necessary because the elaborator tracks heartbeats even when calling kernel evaluation. The +kernel variant uses kernel reduction which itself doesn't consume heartbeats, but the surrounding elaboration code might checkpoint. I've seen some chunks need 4000000 heartbeats, so I'm setting maxHeartbeats to 400000000 globally to be safe, though I'm not entirely sure if that's necessary. | | | | Actually, I should just disable the heartbeat limit entirely with set option maxHeartbeats 0 to avoid any risk of a runaway elaboration burning through hours on a pathological tactic. The kernel has no deterministic timeout anyway. | | | | Now I'll write the generator, making sure to handle the case where N is a huge 13-digit literal, and norm num should handle the proof that 0 < N just fine. After writing the generator, I want to test it with N=23343989 to see if I get localized chunk errors while everything else compiles. Running the full pipeline for N=23M should leave around 1.4M, with roughly 35 chunks plus the z-tree, taking about 4-5 minutes total. | | | | For the test case, I need to find the unique representation of 23343989 by computing the w,x,y,z tuple using Python to verify the solution, then check that errors appear only in the chunks containing that representation while validating everything else compiles. | | Now I'll write the full Spec generator: | | bash | | | | cd /workspace/leanproject && grep -n "^def \|^theorem \|^private \|^noncomputable " Dev/Checker.lean | awk '{print $2}' | tr -d ':' | paste -sd' ' | | | | | | 197 --- TOOL bash --- | | allB allB zero allB succ allB sound t2 p4 c4 p6 c6 p8 c8 t2 def p4 def c4 def p6 def c6 def p8 def c8 def t2 ge one eight t2 c4 mono c6 mono c8 mono maskBit sqAll sqAll sound newtonAux newton bracketOK bracketOK sound mul eqn add eqn sub eqn div eqn mod eqn pow eqn Q1 Q2 Q3 M1 M2 M3 sqAllM1 sqAllM2 sqAllM3 mask1 all mask2 all mask3 all sqTest sqTest sound leafX leafX sound xtreeOK xtreeOK sound leafY leafY sound ytreeOK ytreeOK sound leafZ leafZ sound master choose2 eq choose4 eq choose6 eq choose8 eq A306477 A eq zero test0 d3 d2 xstep xrun xstep sound c4 succ d3 succ d2 succ xrun sound xcheck xcheck sound leafY2 leafY2 sound ytreeOK2 ytreeOK2 sound leafZ2 leafZ2 sound master2 leafX3 c4 alt leafX3 sound xtreeOK3 xtreeOK3 sound leafY3 leafY3 sound ytreeOK3 ytreeOK3 sound leafZ3 leafZ3 sound master3 R1 R2 R3 R4 K1 K2 K3 K4 sqAllK1 sqAllK2 sqAllK3 sqAllK4 maskK1 all maskK2 all maskK3 all maskK4 all sqTest2 beq land zero sqTest2 sound allB4 allB4 sound allBH allBH sound leafX4 notSquare of tests leafX4 sound xtreeOK4 xtreeOK4 sound leafY4 leafY4 sound ytreeOK4 ytreeOK4 sound leafZ4 leafZ4 sound master4 | | | | | | 198 --- ASSISTANT --- | | I'm checking whether choose2 eq and choose4 eq have any problematic dependencies. The choose4 eq definition itself looks clean, relying only on standard factorial and choose properties. But I noticed line 420 uses choose4 eq alongside d3, which appears in a blacklisted section, so I need to be careful about how that's being used. The c4 alt reference is in a different section that should be fine to keep. | | | | Now I'll start writing the generator. | | bash | | | | mkdir -p /workspace/gen && cat /workspace/gen/gen spec.py <<'PYEOF' | | /usr/bin/env python3 | | """Generate the final Submission/Spec.lean disproof file for a given counterexample N.""" | | import sys, re, pickle, argparse | | sys.set int max str digits 2000000 | | | | ROOT="/workspace/leanproject" | | | | def parse units path : | | """split a lean file into declaration units name, text """ | | lines=open path .read .split "\n" | | units= ; cur= ; curname=None; pending= | | def flush : | | nonlocal cur, curname | | if curname is not None: | | units.append curname, "\n".join cur .rstrip | | cur= ; curname=None | | i=0 | | while i < len lines : | | ln=lines i | | m=re.match r'^ def|theorem \s+ A-Za-z0-9 + ', ln | | if m: | | flush | | cur=pending+ ln ; pending= ; curname=m.group 2 | | elif re.match r'^ /--|/- |set option . in$|-- ', ln : | | attachment lines: if we're inside a decl body? decl bodies are indented, these are top-level | | flush | | pending.append ln | | elif re.match r'^ import|namespace|end|open|set option \b', ln : | | flush ; pending= | | elif ln.strip =="" and curname is None: | | pending= | | else: | | if curname is not None: cur.append ln | | else: pending.append ln | | i+=1 | | flush | | return dict units , u 0 for u in units | | | | CHECKER KEEP = """allB allB zero allB succ allB sound t2 p4 c4 p6 c6 p8 c8 t2 def p4 def c4 def p6 def | | c6 def p8 def c8 def t2 ge one eight t2 c4 mono c6 mono c8 mono maskBit sqAll sqAll sound | | newtonAux newton bracketOK bracketOK sound mul eqn add eqn sub eqn div eqn mod eqn pow eqn | | choose2 eq choose4 eq choose6 eq choose8 eq A eq zero c4 alt | | R1 R2 R3 R4 K1 K2 K3 K4 sqAllK1 sqAllK2 sqAllK3 sqAllK4 maskK1 all maskK2 all maskK3 all | | maskK4 all sqTest2 beq land zero sqTest2 sound allB4 allB4 sound allBH allBH sound""".split | | | | def framework text : | | out= | | units, order = parse units f"{ROOT}/Dev/Checker.lean" | | for n in order: | | if n in CHECKER KEEP: | | out.append units n | | blobs | | FLB,OFFB,SELB = pickle.load open "/tmp/blobs.pkl","rb" | | out.append f"def FLB : Nat := {FLB}" | | out.append f"def OFFB : Nat := {OFFB}" | | out.append f"def SELB : Nat := {SELB}" | | for f in "V5Defs","Checker5" : | | units, order = parse units f"{ROOT}/Dev/{f}.lean" | | for n in order: | | out.append units n | | return "\n\n".join out | | | | ---------- arithmetic ---------- | | def c4 x : return x x+1 x+2 x+3 //24 | | def c6 y : return y y+1 y+2 y+3 y+4 y+5 //720 | | def c8 z : return z z+1 z+2 z+3 z+4 z+5 z+6 z+7 //40320 | | C2700=c4 2700 ; C5400=c4 5400 | | | | def log2n v : | | r=0 | | while v =2: v//=2; r+=1 | | return r | | | | def newton isqrt v : | | g=2 log2n v //2+1 ; fuel=64 | | while fuel 0: | | g2= g+v//g //2 | | if g2<g: g=g2; fuel-=1 | | else: return g | | return g | | | | class Gen: | | def init self,N,fy=9,fz=8,cap=40000 : | | self.N=N; self.fy=fy; self.fz=fz; self.cap=cap | | FLB,OFFB,SELB=pickle.load open "/tmp/blobs.pkl","rb" | | self.META= | | for a in range 225 : | | f= FLB 4 a &15 | | self.META.append f | | self.out= | | self.nchunk=0; self.ncomb=0; self.totleaves=0; self.maxchunk=0 | | per z,y leaf counts | | self.zy={} | | self.zleaves= 0 2 fz | | for z in range 2 fz : | | r8=c8 z ; tot=0 | | for y in range 2 fy : | | if N<=r8: | | c=1 | | elif N<=r8+c6 y : | | c=1 | | else: | | W=N-r8-c6 y | | self.validate pair W | | a= 8 W+1 %225; f=self.META a | | c=2 f+1 if W =C2700 else 2 f | | c+=6 | | self.zy z,y =c; tot+=c | | self.zleaves z =tot | | def validate pair self,W : | | checks that the runtime per-pair guards will hold | | assert W < C5400, self.N,W | | xcap=newton isqrt newton isqrt 24 W | | assert W < c4 xcap+1 , "xcap fail",W | | if W =C2700: | | assert W < c4 5400 | | else: | | assert W < c4 2700 | | def emit self,s : self.out.append s | | def emitY self,z,f,a : | | nm=f"yc{z} {f} {a}" | | est=sum self.zy z,y for y in range a,a+2 f | | if est<=self.cap or f==0: | | self.emit f"theorem {nm} : allB leafY5 {self.N} c8 {z} {f} {a} = true := by decide +kernel" | | self.nchunk+=1; self.totleaves+=est; self.maxchunk=max self.maxchunk,est | | else: | | n1=self.emitY z,f-1,a ; n2=self.emitY z,f-1,a+2 f-1 | | self.emit f"""theorem {nm} : allB leafY5 {self.N} c8 {z} {f} {a} = true := by | | rw show {f}:Nat = {f-1}+1 from rfl, allB succ | | rw show {a}:Nat + 2^{f-1} = {a+2 f-1 } by norm num | | rw {n1}, {n2} | | rfl""" | | self.ncomb+=1 | | return nm | | def emitZ self,f,a : | | nm=f"zc{f} {a}" | | est=sum self.zleaves z for z in range a,a+2 f | | if est<=self.cap: | | self.emit f"theorem {nm} : allB leafZ5 {self.N} {self.fy} {f} {a} = true := by decide +kernel" | | self.nchunk+=1; self.totleaves+=est; self.maxchunk=max self.maxchunk,est | | elif f==0: | | z=a | | yroot=self.emitY z,self.fy,0 | | self.emit f"theorem ez{z} : Nat.ble {self.N} c8 {z} = false := by decide +kernel" | | self.emit f"theorem bz{z} : Nat.ble {self.N} Nat.add c8 {z} c6 Nat.pow 2 {self.fy} = true := by decide +kernel" | | self.emit f"""theorem {nm} : allB leafZ5 {self.N} {self.fy} 0 {z} = true := by | | rw allB zero | | simp only leafZ5 | | rw ez{z}, cond false | | simp only ytreeOK5 | | rw {yroot}, bz{z} | | rfl""" | | self.ncomb+=1 | | else: | | n1=self.emitZ f-1,a ; n2=self.emitZ f-1,a+2 f-1 | | self.emit f"""theorem {nm} : allB leafZ5 {self.N} {self.fy} {f} {a} = true := by | | rw show {f}:Nat = {f-1}+1 from rfl, allB succ | | rw show {a}:Nat + 2^{f-1} = {a+2 f-1 } by norm num | | rw {n1}, {n2} | | rfl""" | | self.ncomb+=1 | | return nm | | def run self : | | assert self.N <= c8 2 self.fz | | assert self.N <= c6 2 self.fy ensures Bz true for all z r8 =0 | | zroot=self.emitZ self.fz,0 | | self.emit f"theorem htop5 : Nat.ble {self.N} c8 Nat.pow 2 {self.fz} = true := by decide +kernel" | | self.emit f"theorem hall5 : ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ {self.N} :=\n master5 {zroot} htop5" | | self.emit f"theorem a306477 zero : A306477 {self.N} = 0 :=\n A eq zero hall5" | | return "\n\n".join self.out | | | | HEADER = '''import FormalConjectures.Util.ProblemImports | | | | set option Elab.async false | | set option maxHeartbeats 0 | | set option linter.unusedVariables false | | | | open Nat Finset | | | | /-- | | A306477: Number of ways to write $n$ as $\\binom{w+2}{2} + \\binom{x+3}{4} + \\binom{y+5}{6} + \\binom{z+7}{8}$ | | with $w,x,y,z$ nonnegative integers, where $\\binom{m}{k}$ denotes the binomial coefficient $\\frac{m }{k m-k }$. | | -/ | | def A306477 n : ℕ : ℕ := | | let R := Finset.range n + 1 | | R.sum fun w = | | R.sum fun x = | | R.sum fun y = | | R.sum fun z = | | if w + 2 .choose 2 + x + 3 .choose 4 + y + 5 .choose 6 + z + 7 .choose 8 = n then 1 else 0 | | | | | | | | | | | | namespace D | | ''' | | | | def footer N : | | return f'''end D | | | | /-- | | Disproof of the conjecture OEIS A306477, Zhi-Wei Sun's "2-4-6-8 conjecture" : | | {N} is a counterexample: it has no representation as | | $\\binom{{w+2}}{{2}} + \\binom{{x+3}}{{4}} + \\binom{{y+5}}{{6}} + \\binom{{z+7}}{{8}}$. | | -/ | | theorem oeis 306477 conjecture 1.disproof : ¬ ∀ n : ℕ, 0 < n → 0 < A306477 n := by | | intro h | | have h2 := h {N} by norm num | | rw D.a306477 zero at h2 | | exact Nat.lt irrefl 0 h2 | | ''' | | | | if name ==" main ": | | ap=argparse.ArgumentParser | | ap.add argument "N",type=int | | ap.add argument "--out",default="/tmp/SpecGen.lean" | | ap.add argument "--cap",type=int,default=40000 | | args=ap.parse args | | g=Gen args.N,cap=args.cap | | body=g.run | | text=HEADER+"\n"+framework text +"\n\n"+body+"\n\n"+footer args.N | | open args.out,"w" .write text | | print f"chunks={g.nchunk} combiners={g.ncomb} totleaves={g.totleaves} maxchunk={g.maxchunk}" | | print f"est kernel time {g.totleaves 160e-6/60:.1f} min; wrote {args.out} {len text /1e6:.2f} MB " | | PYEOF | | python3 /workspace/gen/gen spec.py 23343989 --out /tmp/SpecTest.lean | | | | | | 198 --- TOOL bash --- | | chunks=33 combiners=32 totleaves=841380 maxchunk=39290 | | est kernel time 2.2 min; wrote /tmp/SpecTest.lean 0.66 MB | | | | | | 199 --- ASSISTANT --- | | I've generated a test file for N=23343989, which should have exactly one representation, meaning one chunk will fail during compilation. Before running the test, I need to find the specific coefficients w,x,y,z that satisfy t2w+c4x+c6y+c8z = 23343989 so I can predict which chunks will contain errors. | | bash | | | | cd /tmp && python3 - <<'EOF' | | from sim import c4,c6,c8 | | import math | | N=23343989 | | sols= | | z=0 | | while c8 z <=N: | | y=0 | | while c8 z +c6 y <=N: | | x=0 | | while c8 z +c6 y +c4 x <=N: | | W=N-c8 z -c6 y -c4 x | | v=8 W+1 | | r=math.isqrt v | | if r r==v and r =3 and r%2==1: | | sols.append z,y,x, r-3 //2 | | x+=1 | | y+=1 | | z+=1 | | print sols | | EOF | | | | | | 199 --- TOOL bash --- | | 27, 35, 73, 363 | | | | | | 200 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && cp /tmp/SpecTest.lean Dev/SpecTest.lean && sed -i 's/import FormalConjectures.Util.ProblemImports/import FormalConjectures.Util.ProblemImports/' Dev/SpecTest.lean && nohup bash -c 'time lake env lean Dev/SpecTest.lean' /tmp/st.log 2 &1 & echo started; sleep 240; grep -c error /tmp/st.log; grep error /tmp/st.log | head -20; tail -2 /tmp/st.log | | | | | | 200 --- TOOL bash --- | | started | | 0 | | | | | | 201 --- ASSISTANT --- | | bash | | | | sleep 240; grep -c error /tmp/st.log; grep error /tmp/st.log | head; tail -3 /tmp/st.log; ps -C lean -o pid,rss,etime | tail -2 | | | | | | 201 --- TOOL bash --- | | 0 | | 7114 0 01:27:43 | | 11011 6444508 08:07 | | | | | | 202 --- ASSISTANT --- | | The compilation is still running after 8 minutes with memory usage holding steady, though the kernel work is taking longer than expected due to CPU contention. I'll wait for it to finish while checking on the scan99c progress in the meantime. | | bash | | | | sleep 240; tail -3 /tmp/st.log; grep -n error /tmp/st.log | head; tail -2 /tmp/scan99c.err | | | | | | 202 --- TOOL bash --- | | block 2/34 done marks=167977771304 zeros=0 | | block 3/34 done marks=168807556469 zeros=0 | | | | | | 203 --- ASSISTANT --- | | bash | | | | sleep 300; tail -3 /tmp/st.log; grep -n error /tmp/st.log | head -8; ps -C lean -o pid,rss,etime | tail -1 | | | | | | 203 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 204 --- ASSISTANT --- | | bash | | | | tail -3 /tmp/st.log; grep -n error /tmp/st.log | head -8; ps -C lean -o pid,rss,etime | tail -1 | | | | | | 204 --- TOOL bash --- | | 11011 7709800 17:30 | | | | | | 205 --- ASSISTANT --- | | I've been running this for 17.5 minutes without output yet, and the memory usage is climbing from 6.4GB to 7.7GB—that's concerning. The test file has Elab.async false set, which should help, but there seems to be some accumulation happening per theorem, possibly from small leaks adding up across the 33 characters or so of each declaration. | | | | Now I'm realizing the memory situation is getting critical—with scan99c already at 3.6GB and my current usage at 7.7GB, I'm approaching or possibly exceeding the 10GB cgroup limit, which would put the total around 11.3GB. I need to check if I'm hitting that boundary. | | bash | | | | cat /sys/fs/cgroup/memory.current; ps -C scan99 -o rss=; sleep 200; tail -2 /tmp/st.log; ps -C lean -o rss= | tail -1 | | | | | | 205 --- TOOL bash --- | | 6358241280 | | 3574180 | | 7596416 | | | | | | 206 --- ASSISTANT --- | | Looking at the memory metrics more carefully — the cgroup shows 6.36GB current usage, but RSS reports 7.6GB plus scan at 3.6GB which would total over 11GB. The discrepancy makes sense because RSS double-counts shared pages from memory-mapped files that live in the page cache rather than anonymous memory, so the actual anonymous usage is significantly lower than RSS suggests. The cgroup's 6.36GB reading is actually comfortable, though the earlier OOM kills occurred when memory.peak spiked to 10.7GB during a larger scan operation. | | | | The compilation is still running at around 20 minutes, which is much longer than the estimated 2.2 minutes for the kernel alone. Once it finishes I should check the user-time breakdown to understand where the slowdown is coming from — could be the framework elaboration combined with 65 theorems involving rewrite chains, or possibly contention from the 35% CPU usage. | | bash | | | | sleep 270; tail -2 /tmp/st.log; grep -n error /tmp/st.log|head; ps -C lean -o rss=,etime= | tail -1 | | | | | | 206 --- TOOL bash --- | | user 7m35.505s | | sys 0m5.965s | | 19:Dev/SpecTest.lean:1061:60: error: Error pretty printing: maximum recursion depth has been reached | | 0 01:45:15 | | | | | | 207 --- ASSISTANT --- | | bash | | | | grep -n "error" /tmp/st.log | awk -F: '{print $2":"$3}' | head -20; echo; grep -B2 -A3 "^Dev/SpecTest.lean:1061" /tmp/st.log | head; sed -n 1,18p /tmp/st.log | | | | | | 207 --- TOOL bash --- | | Dev/SpecTest.lean:1061 | | | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/SpecTest.lean:1061:60: error: Error pretty printing: maximum recursion depth has been reached | | use set option maxRecDepth <num to increase limit | | use set option diagnostics true to get diagnostic information | | | | Dev/SpecTest.lean:108:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/SpecTest.lean:108:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/SpecTest.lean:114:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/SpecTest.lean:114:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | Dev/SpecTest.lean:120:13: warning: this tactic is never executed | | | | Note: This linter can be disabled with set option linter.unreachableTactic false | | Dev/SpecTest.lean:120:13: warning: 'omega' tactic does nothing | | | | Note: This linter can be disabled with set option linter.unusedTactic false | | | | | | 208 --- ASSISTANT --- | | There's exactly one error at line 1061 — a failing decide statement with the values z=27 and y=35 that's producing a false chunk when true was expected, though the error message has some pretty-printing recursion issues. The user time came in at 7m35s, well above the 2.2 minute estimate, likely due to elaboration overhead from the framework components rather than contention. | | | | Breaking down the timing: the framework itself accounts for roughly 250 seconds including COMP chunks which total around 200 seconds and run on every compile , the actual chunks take about 130 seconds 841K leaves at 160 microseconds each , and elaboration adds another 70 seconds — the math checks out to the observed 455 seconds. At the final scale with 6 trillion nodes, I'm looking at 54 million leaves which would take about 2.4 hours plus the COMP overhead and framework time, which is acceptable. I need to verify that line 1061 is indeed the right chunk and confirm there are no other errors. | | bash | | | | sed -n 1055,1065p /workspace/leanproject/Dev/SpecTest.lean; grep -c "error" /tmp/st.log | | | | | | 208 --- TOOL bash --- | | rw show 24:Nat + 2^0 = 25 by norm num | | rw zc0 24, zc0 25 | | rfl | | | | theorem zc0 26 : allB leafZ5 23343989 9 0 26 = true := by decide +kernel | | | | theorem zc0 27 : allB leafZ5 23343989 9 0 27 = true := by decide +kernel | | | | theorem zc1 26 : allB leafZ5 23343989 9 1 26 = true := by | | rw show 1:Nat = 0+1 from rfl, allB succ | | rw show 26:Nat + 2^0 = 27 by norm num | | 1 | | | | | | 209 --- ASSISTANT --- | | The error is isolated to just one chunk at z=27 where that specific unique representation lives, while everything else compiled successfully. But I'm realizing that combiners depending on this failed chunk should also fail since they'd be working with an errored theorem — unless Lean adds failed theorems as sorry axioms anyway, which would let dependent chunks still compile. | | | | So the validation checks out: the generator produces a working file, and on a genuine counterexample there'd be zero errors. Now I'm waiting for the scan to find N0 currently at block 3/34 with no zeros found yet around 7.2e12 , and once it does I need to write a C verifier, run a parallel Python simulation of all chunk pairs to confirm they're true, then generate the real Spec.lean file with that N0 value and verify it compiles cleanly before moving it to the submission folder. | | | | I should also check the axioms on the framework theorems themselves—things like the passing chunks and the core soundness proofs—by creating a small test file that imports the checker and prints out what axioms those theorems depend on. | | Exactly one error at zc0 27 — precisely the chunk containing the unique representation z=27 . The machinery is fully validated. Let me check axioms of the framework theorems: | | bash | | | | cd /workspace/leanproject && cat /tmp/ax.lean <<'EOF' | | import Checker5 | | open D | | print axioms comp true | | print axioms xtreeOK5 sound | | print axioms master5 | | print axioms A eq zero | | print axioms sqTest2 sound | | EOF | | lake env sh -c 'LEAN PATH=$LEAN PATH:devlib lean /tmp/ax.lean' 2 &1 | head -12 | | | | | | 209 --- TOOL bash --- | | 'D.comp true' depends on axioms: propext | | 'D.xtreeOK5 sound' depends on axioms: propext, Classical.choice, Quot.sound | | 'D.master5' depends on axioms: propext, Classical.choice, Quot.sound | | 'D.A eq zero' depends on axioms: propext, Classical.choice, Quot.sound | | 'D.sqTest2 sound' depends on axioms: propext, Classical.choice, Quot.sound | | | | | | 210 --- ASSISTANT --- | | I'm setting up an independent C verifier that will test candidate values without relying on shared code from the main scan. The verifier loops through constrained ranges for variables and checks whether expressions of the form 8W+1 yield perfect squares using integer square root calculations, confirming there are no solutions. | | All axioms check out as allowed. Now I'll write the independent verifier for candidate counterexamples. | | bash | | | | cat /tmp/verify.c <<'EOF' | | // Independent exhaustive verifier: does N have a representation T w +C4+C6+C8 with T positive triangular? | | include <stdio.h | | include <stdlib.h | | include <stdint.h | | include <math.h | | typedef unsigned int128 u128; | | typedef uint64 t u64; | | static u64 isq u64 x {u64 r= u64 sqrtl long double x ; while r&&r r x r--; while r+1 r+1 <=x r++; return r;} | | int main int argc,char argv { | | u64 N=strtoull argv 1 ,0,10 ; | | long cnt=0; u64 checked=0; | | for u64 z=0;;z++ { | | u128 c8= u128 z z+1 z+2 z+3 z+4 z+5 z+6 z+7 /40320; | | if c8 N break; | | for u64 y=0;;y++ { | | u128 c6= u128 y y+1 y+2 y+3 y+4 y+5 /720; | | if c8+c6 N break; | | for u64 x=0;;x++ { | | u128 c4= u128 x x+1 x+2 x+3 /24; | | u128 s=c8+c6+c4; | | if s N break; | | u64 W= u64 N-s ; // W = t2 w required, t2 =1 | | u64 v=8 W+1; | | u64 r=isq v ; | | checked++; | | if r r==v && r =3 { cnt++; printf "SOLUTION z=%llu y=%llu x=%llu r=%llu\n", unsigned long long z, unsigned long long y, unsigned long long x, unsigned long long r ; } | | } | | } | | } | | printf "N=%llu triples=%llu solutions=%ld = A306477 N %s 0\n", unsigned long long N, unsigned long long checked,cnt,cnt?" ":"=" ; | | return 0; | | } | | EOF | | gcc -O2 -o /tmp/verify /tmp/verify.c -lm && /tmp/verify 23343989 && /tmp/verify 394239767; tail -2 /tmp/scan99c.err | | | | | | 210 --- TOOL bash --- | | SOLUTION z=27 y=35 x=73 r=729 | | N=23343989 triples=186163 solutions=1 = A306477 N 0 | | SOLUTION z=38 y=38 x=237 r=17385 | | N=394239767 triples=910232 solutions=1 = A306477 N 0 | | block 3/34 done marks=168807556469 zeros=0 | | block 4/34 done marks=168185931097 zeros=0 | | | | | | 211 --- ASSISTANT --- | | The verifier is working and confirming known cases. I'm currently at block 4 out of 34, having scanned up to around 7.65e12, with no zeros found yet. At the current pace of 10-11 minutes per block, the remaining 30 blocks should take roughly 5.5 hours to reach 2e13. While the scan continues, I'm thinking about potential optimizations—the process is hitting about 400% CPU usage due to host contention, which limits what we can improve there. Another angle would be scanning sibling classes in parallel, like classes 20 and 53 modulo 99. | | | | Reconsidering the probability model: the expected number of zeros in class 86 mod 99 across the range 5.5e12, 2e13 was estimated to be plausible around 10^12 to 10^13, and we're currently at 7.6e12 with nothing yet, so it makes sense to keep going. On the kernel optimization front, I'm recalculating the leaf count and timing—my earlier measurements of 151-160 microseconds per leaf included both cheap and full leaves, so I need to reestimate the total leaves at 8e12 to see if there's meaningful room for improvement there. So the key insight is that sortedness within each class lets me binary search for the cutoff index at runtime—I don't need correctness, just some boundary. Once I find that index i , sortedness guarantees everything beyond it exceeds the limit, so I only need one verification check. Then I can build a variable-length tree covering just the slots before the cutoff, using an interval-tree structure that adapts to whatever i turns out to be. | | | | The savings are substantial: roughly 55% of leaves become cheap 40–50μs instead of the skip cost , which compounds to maybe 25–35% total speedup—bringing 5.8 hours down to around 4 hours at the target scale. The implementation is tractable: proving sortedness across the 225×2048 cases, defining the adaptive interval tree with soundness, and verifying the tree construction. It's worth pursuing once I know whether N0 exceeds ~8e12. | | | | There's also a secondary optimization: the FULL leaf cost dominates about two-thirds of runtime, with operations around 26 plus tree overhead of ~8. GMP operations on small naturals are cheap... Extracting the c-value from the blob and comparing it directly against A8 gives me a cheap guard to skip computation — if c exceeds the threshold, v becomes zero and I exit early. This saves the full xcap comparison and shaves off another ~13 microseconds by eliminating the x computation entirely, leaving just the slot extraction and basic arithmetic. | | | | For the k=1 case, I can avoid duplicating slot enumeration by giving each k value its own cutoff index in the sorted tree structure — k=0 gets one bound, k=1 gets another based on which slots actually matter for the smaller prefix range. | | | | Now I'm estimating the leaf traversal cost: with full-only leaves around 23.5M to 64.6M entries, each taking roughly 150 microseconds to scan, that's somewhere between 1 to 2.7 hours total. This is definitely worth implementing while I'm already scanning the data. I need to carefully design the sortedness invariant and the tree structure to handle sentinel values correctly — once a slot becomes 4095 it stays that way, and I need to track which slots are valid versus which are padding. Defining the verification function... Implementing binary search logic... I'm defining a recursive function that checks if a predicate holds for all indices in a range, using fuel-based recursion to handle variable-size trees. The base case returns true when the range is empty, and for larger ranges it splits the interval in half and recursively checks both halves. With fuel set to 13, this handles the necessary depth for the problem constraints. Refining the guard logic for the leaf construction—the sentinel and capacity checks are cheap insurance that won't actually trigger since real slots stay below 2700, but keeping them ensures soundness. Now moving into the k=1 case with a conditional check on the boundary condition. I'm checking whether the index has reached the boundary or if the limit is exceeded, then constructing the result by combining the tree with coverage checks for different ranges of x and W, making sure to handle the case where W is below the threshold for k=1 by adding a conditional check based on which branch was taken. The runtime per pair works out to about 0.8 milliseconds, which scales to roughly 44 seconds across all pairs—acceptable. The savings are substantial: at the larger dataset sizes, this cuts the processing time from over 2 hours down to around 1 hour, and from nearly 6 hours to under 3 hours. It's worth building out, requiring about 150 lines of Lean code plus some additions to the generator and simulator. I'll create a new module that imports the existing definitions and adds the sorting logic there, since the cached object files would otherwise need rebuilding. | | | | Now I'm setting up the implementation plan: first I'll write a Python simulator that validates the new cut and allI semantics against the existing version to ensure they agree on pass/fail outcomes and leaf counts, then build out the Lean definitions for the new tree structures and proof framework. | | The scan is ongoing. I'm now implementing v6, which uses prefix-pruned enumeration with sortedness and binary-search cutoffs to reduce kernel time by about 2.3x, starting with the exact simulator. | | bash | | | | cat /tmp/sim6.py <<'EOF' | | v6: prefix-pruned slot enumeration. Mirrors planned Lean defs exactly. | | from sim5 import fla, cbof, META | | from sim import K2,K3,K4,R2,R3,R4, c4,c6,c8, log2n, newton, S, bracketOK | | | | C2700=c4 2700 ; C5400=c4 5400 | | def slot CB,i : return CB 12 i &4095 | | | | def cut CB,lim,fuel,lo,hi : | | while fuel 0: | | if hi<=lo: return lo | | mid= lo+hi //2 | | if slot CB,mid <=lim: lo=mid+1 | | else: hi=mid | | fuel-=1 | | return lo | | | | def sqT v : | | S.sq2+=1 | | if K2 v%R2 &1==0: return True | | if K3 v%R3 &1==0: return True | | if K4 v%R4 &1==0: return True | | return bracketOK v | | | | def leafX6 A8,CB,k,i : | | S.xleaf+=1 | | e=slot CB,i | | if 2700<=e: return True | | x=2700 k+e | | t=x x+3 ; c=t t+2 //24 | | v=A8-8 c | | if v<0: v=0 | | if v<=1: return True | | return sqT v | | | | def allI p,fuel,a,n : | | mirrors Lean fuel-rec; here iterative for speed | | if fuel<=0: return n==0 | | for i in range a,a+n : | | if not p i : return False | | return True | | | | def xtreeOK6 W : | | S.pairs+=1 | | A8=8 W+1; a=A8%225; f=fla a ; CB=cbof a | | xcap=newton newton 24 W | | if not W < c4 xcap+1 : return False | | i0=cut CB,xcap,f+2,0,2 f | | if not i0==2 f or xcap<slot CB,i0 : return False | | if not allI lambda i: leafX6 A8,CB,0,i ,13,0,i0 : return False | | if C2700<=W: | | if not W < C5400: return False | | lim1=xcap-2700 | | assert xcap =2700 | | i1=cut CB,lim1,f+2,0,2 f | | if not i1==2 f or lim1<slot CB,i1 : return False | | if not allI lambda i: leafX6 A8,CB,1,i ,13,0,i1 : return False | | else: | | if not W < C2700: return False | | return True | | | | def leafY6 N,r8,y : | | b=r8+c6 y | | if N<=b: return True | | return xtreeOK6 N-b | | | | def ytreeOK6 N,fy,r8 : | | if not N<=r8+c6 2 fy : return False | | return all leafY6 N,fy r8y 0 ,y for y in range 2 fy if False else all leafY6 N,r8,y for y in range 2 fy | | | | def leafZ6 N,fy,z : | | r8=c8 z | | if N<=r8: return True | | if not N<=r8+c6 2 fy : return False | | return all leafY6 N,r8,y for y in range 2 fy | | | | def master6 N,fy=9,fz=8 : | | if not N<=c8 2 fz : return False | | return all leafZ6 N,fy,z for z in range 2 fz | | | | exact leaf counter without executing python-slow full master when only counts needed | | def count pair W : | | a= 8 W+1 %225; L,f,off=META a ; CB=cbof a | | xcap=newton newton 24 W | | i0=cut CB,xcap,f+2,0,2 f | | n=i0 | | if C2700<=W: | | n+=cut CB,xcap-2700,f+2,0,2 f | | return n | | | | if name ==" main ": | | import sys | | N=int sys.argv 1 | | print N, master6 N | | print "pairs",S.pairs,"xleaf",S.xleaf,"sq2",S.sq2,"bracket",S.brk | | EOF | | cd /tmp && python3 sim6.py 23343989; python3 - <<'EOF' | | cross-validate xtreeOK6 vs xtreeOK5 on random W | | import random, sim5, sim6 | | random.seed 2 | | bad=0 | | for t in range 4000 : | | W=random.randint 1,6 10 12 | | r5=sim5.xtreeOK5 W ; r6=sim6.xtreeOK6 W | | if r5 =r6: bad+=1; print "MISMATCH",W,r5,r6 | | print "done mismatches",bad | | leaf count estimate at scale | | from sim import c6,c8 | | def count N,fy=9,fz=8 : | | tot=0 | | for z in range 2 fz : | | r8=c8 z | | if N<=r8: continue | | for y in range 2 fy : | | b=r8+c6 y | | if N<=b: continue | | tot+=sim6.count pair N-b +8 | | return tot | | for N in 5527622910038, 8000000000000, 13000000000000 : | | print N, "v6 leaves", count N | | EOF | | | | | | 211 --- TOOL bash --- | | 23343989 False | | pairs 1331 xleaf 25817 sq2 25636 bracket 249 | | done mismatches 0 | | 5527622910038 v6 leaves 24006346 | | 8000000000000 v6 leaves 37051412 | | 13000000000000 v6 leaves 75999271 | | | | | | 212 --- ASSISTANT --- | | The v6 semantics check validates against v5 with 4000 random samples, and I'm seeing significantly lower leaf counts across the board—24M instead of 54M at the lower bound, 37M versus 85M in the middle range, and 76M compared to 134M at the high end. At roughly 150 microseconds per leaf, that translates to processing times of about 1 to 3.2 hours depending on the scale. The 76M figure aligns closely with my earlier full estimate of 64.6M when accounting for slots at or below the capacity threshold. | | | | Now I'm implementing the Lean definitions and checker, starting with helper functions to extract slot values from the bit-packed representation and verify that slots are sorted in ascending order within each range. The main SORTALL theorem checks this property across all 225 entries, but the proof is computationally intensive—roughly 164,000 leaves with significant memory overhead—so I'll need to split it into four chunks to keep it manageable. Continuing the induction step by working through the guard conditions and establishing that the leaf at index j provides the necessary comparison between consecutive slots. | | | | Now I'm defining a binary search function that recursively narrows down a range based on slot comparisons against a limit value, using a midpoint calculation to guide the search direction. Defining the allI function... Now I'm verifying the range splitting works correctly when n ≥ 2, confirming the two recursive calls cover the full interval. Then I'm defining a function that checks a slot value against a threshold and performs a series of arithmetic operations—multiplying, dividing, and subtracting—before running a test on the result. | | | | I'm establishing a soundness theorem that mirrors the previous one, showing that if the function returns true under certain constraints on the slot value and computed intermediate values, then a specific inequality holds. After that, I'm setting up a tree validation function that initializes an 8-scaled value, computes its modulo and corresponding parameters, then begins constructing the necessary data structures. | | | | Continuing with the validation logic... I'm working through the case analysis on whether W is bounded by c4 2700, splitting into scenarios where either x stays below 2700 or extends up to 5400, then setting up the quotient and remainder when dividing by 2700. For the colFree case, I'm checking if I can extract the mask contradiction logic into a reusable lemma rather than duplicating the reasoning from the v5 proof. | | | | Now I'm handling the false branch where the composition spec and bsA soundness give me an index i with a leaf constraint, then splitting on whether i falls below or above the cutoff i k for this particular k value—if it's below the cutoff the tree coverage contradicts the leaf bound, and if it's above I need to verify that the element at that index exceeds the limit using the sorted array soundness. Defining the leaf and tree structure functions... I'm simplifying the approach by removing the ytreeOK6 definition and instead using a cases analysis on the ble check to handle both branches, which feeds into the ytree6 parts proof. I'm also organizing the code into a SORTALL structure with four chunks plus a combiner, then generating V6Defs.lean for the definitions and Checker6.lean for the proofs, with a --v6 flag to emit the leafY6 and leafZ6 names. | | The v6 version validated successfully in simulation with improved performance metrics. Now I'll write out the Lean v6 files. | | bash | | | | cd /workspace/leanproject && cat Dev/V6Defs.lean <<'EOF' | | import Checker5 | | set option linter.style.moduleDocstring false | | set option maxHeartbeats 4000000 | | | | /- v6: prefix-pruned slot enumeration using sortedness of slot lists. -/ | | | | namespace D | | | | def slotC CB i : Nat : Nat := Nat.land Nat.shiftRight CB Nat.mul 12 i 4095 | | | | def sortA CB f : Nat : Bool := | | allBH fun i = cond Nat.ble Nat.pow 2 f Nat.add i 1 true | | Nat.ble slotC CB i slotC CB Nat.add i 1 f 0 | | | | def sortG : Nat → Bool := fun a = cond Nat.ble 225 a true sortA cbof a fla a | | | | def SORTALL : Bool := allB sortG 8 0 | | | | theorem sortT 0 : allB sortG 6 0 = true := by decide +kernel | | theorem sortT 1 : allB sortG 6 64 = true := by decide +kernel | | theorem sortT 2 : allB sortG 6 128 = true := by decide +kernel | | theorem sortT 3 : allB sortG 6 192 = true := by decide +kernel | | | | theorem sortL 0 : allB sortG 7 0 = true := by | | rw show 7:Nat = 6+1 from rfl, allB succ | | rw show 0:Nat + 2^6 = 64 by norm num | | rw sortT 0, sortT 1 | | rfl | | theorem sortL 1 : allB sortG 7 128 = true := by | | rw show 7:Nat = 6+1 from rfl, allB succ | | rw show 128:Nat + 2^6 = 192 by norm num | | rw sortT 2, sortT 3 | | rfl | | theorem sortall true : SORTALL = true := by | | rw SORTALL, show 8:Nat = 7+1 from rfl, allB succ | | rw show 0:Nat + 2^7 = 128 by norm num | | rw sortL 0, sortL 1 | | rfl | | | | /-- binary search for the first index with slot value lim assuming sorted ; | | correctness is never assumed, only runtime-checked facts are used. -/ | | def cutC CB lim : Nat : Nat → Nat → Nat → Nat := fun fuel = | | Nat.rec motive := fun = Nat → Nat → Nat | | fun lo = lo | | fun ih lo hi = | | cond Nat.ble hi lo lo | | let mid := Nat.div Nat.add lo hi 2 | | cond Nat.ble slotC CB mid lim ih Nat.add mid 1 hi ih lo mid | | fuel | | | | /-- bounded forall over the interval a, a+n , binary splitting, fuel-driven. -/ | | def allI p : Nat → Bool : Nat → Nat → Nat → Bool := fun fuel = | | Nat.rec motive := fun = Nat → Nat → Bool | | fun n = Nat.beq n 0 | | fun ih a n = | | cond Nat.ble n 1 cond Nat.beq n 0 true p a | | let h := Nat.div n 2 | | ih a h .and ih Nat.add a h Nat.sub n h | | fuel | | | | def leafX6 A8 CB k i : Nat : Bool := | | let e := slotC CB i | | cond Nat.ble 2700 e true | | let x := Nat.add Nat.mul 2700 k e | | let t := Nat.mul x Nat.add x 3 | | let c := Nat.div Nat.mul t Nat.add t 2 24 | | let v := Nat.sub A8 Nat.mul 8 c | | cond Nat.ble v 1 true sqTest2 v | | | | def xtreeOK6 W : Nat : Bool := | | let A8 := Nat.add Nat.mul 8 W 1 | | let a := Nat.mod A8 225 | | let f := fla a | | let CB := cbof a | | let xcap := newton newton Nat.mul 24 W | | let i0 := cutC CB xcap Nat.add f 2 0 Nat.pow 2 f | | Nat.blt W c4 Nat.add xcap 1 .and | | cond Nat.beq i0 Nat.pow 2 f true Nat.blt xcap slotC CB i0 .and | | allI leafX6 A8 CB 0 13 0 i0 .and | | cond Nat.ble c4 2700 W | | Nat.blt W c4 5400 .and | | let i1 := cutC CB Nat.sub xcap 2700 Nat.add f 2 0 Nat.pow 2 f | | cond Nat.beq i1 Nat.pow 2 f true | | Nat.blt Nat.sub xcap 2700 slotC CB i1 .and | | allI leafX6 A8 CB 1 13 0 i1 | | Nat.blt W c4 2700 | | | | def leafY6 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK6 Nat.sub N b | | | | def leafZ6 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true | | allB leafY6 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | end D | | EOF | | nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/V6Defs.lean -o devlib/V6Defs.olean"' /tmp/v6d.log 2 &1 & echo bg | | | | | | 212 --- TOOL bash --- | | bg | | | | | | 213 --- ASSISTANT --- | | Now I'll work through the v6 soundness proofs. | | bash | | | | cd /workspace/leanproject && cat Dev/Checker6.lean <<'EOF' | | import V6Defs | | set option linter.style.moduleDocstring false | | set option maxHeartbeats 1000000 | | | | namespace D | | | | theorem sortall spec : ∀ a, a < 225 → sortA cbof a fla a = true := by | | intro a ha | | have h := allB sound 0 sortall true a Nat.zero le by omega | | simp only sortG at h | | have hble : Nat.ble 225 a = false := by | | cases hb : Nat.ble 225 a with | | | true = rw Nat.ble eq at hb; omega | | | false = rfl | | rw hble, cond false at h | | exact h | | | | theorem sortA sound {CB f : Nat} h : sortA CB f = true : | | ∀ i j, i ≤ j → j < 2^f → slotC CB i ≤ slotC CB j := by | | intro i j hij hj | | induction j with | | | zero = | | have : i = 0 := by omega | | simp this | | | succ j ih = | | rcases Nat.eq or lt of le hij with rfl | hlt | | · exact Nat.le refl | | · have hstep := allBH sound 0 h j Nat.zero le by omega | | have hg : Nat.ble Nat.pow 2 f Nat.add j 1 = false := by | | cases hb : Nat.ble Nat.pow 2 f Nat.add j 1 with | | | true = | | rw Nat.ble eq at hb | | simp only pow eqn, add eqn at hb | | omega | | | false = rfl | | rw hg, cond false, Nat.ble eq at hstep | | have hj' : slotC CB i ≤ slotC CB j := ih by omega by omega | | have : Nat.add j 1 = j + 1 := rfl | | rw this at hstep | | omega | | | | theorem allI sound {p : Nat → Bool} : ∀ fuel a n : Nat , allI p fuel a n = true → | | ∀ i, a ≤ i → i < a + n → p i = true := by | | intro fuel | | induction fuel with | | | zero = | | intro a n h i h1 h2 | | have : Nat.beq n 0 = true := h | | rw Nat.beq eq at this | | omega | | | succ fuel ih = | | intro a n h i h1 h2 | | have hs : allI p fuel+1 a n = | | cond Nat.ble n 1 cond Nat.beq n 0 true p a | | allI p fuel a Nat.div n 2 .and | | allI p fuel Nat.add a Nat.div n 2 Nat.sub n Nat.div n 2 := rfl | | rw hs at h | | cases hb : Nat.ble n 1 with | | | true = | | rw Nat.ble eq at hb | | rw ← Nat.ble eq at hb | | rw hb, cond true at h | | have hn1 : n ≤ 1 := by rw ← Nat.ble eq ; exact hb | | cases hz : Nat.beq n 0 with | | | true = rw Nat.beq eq at hz; omega | | | false = | | rw hz, cond false at h | | have hz' : n ≠ 0 := by | | intro hcon | | rw hcon at hz | | simp at hz | | have : i = a := by omega | | rwa this | | | false = | | rw hb, cond false, Bool.and eq true at h | | obtain ⟨hL, hR⟩ := h | | have hn2 : ¬ n ≤ 1 := by rw ← Nat.ble eq, hb ; simp | | rcases Nat.lt or ge i a + n/2 with hc | hc | | · exact ih a Nat.div n 2 hL i h1 by simp only div eqn ; omega | | · refine ih Nat.add a Nat.div n 2 Nat.sub n Nat.div n 2 hR i ? ? | | · simp only add eqn, div eqn ; omega | | · simp only add eqn, div eqn, sub eqn ; omega | | | | theorem leafX6 sound {W CB k i : Nat} h : leafX6 8 W+1 CB k i = true | | e x : Nat hedef : e = slotC CB i hxdef : x = 2700 k + e | | helt : e < 2700 : | | ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | have hc4 := c4 alt x | | simp only leafX6 at h | | rw ← hedef at h | | have hble : Nat.ble 2700 e = false := by | | cases hb : Nat.ble 2700 e with | | | true = rw Nat.ble eq at hb; omega | | | false = rfl | | rw hble, cond false at h | | have hxdef' : Nat.add Nat.mul 2700 k e = x := by | | simp only add eqn, mul eqn ; omega | | rw hxdef' at h | | simp only hc4 at h | | cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | | true = | | rw Nat.ble eq at hb | | simp only sub eqn, mul eqn at hb | | omega | | | false = | | rw hb, cond false at h | | have hlt : ¬ Nat.sub 8 W+1 Nat.mul 8 c4 x ≤ 1 := by | | rw ← Nat.ble eq, hb ; simp | | simp only sub eqn, mul eqn at hlt | | have hv : Nat.sub 8 W+1 Nat.mul 8 c4 x = 2 w+3 2 w+3 := by | | simp only sub eqn, mul eqn | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | rw hv at h | | exact sqTest2 sound h 2 w+3 rfl | | | | /-- the mask column-free case: if colFree a e then no w works for any x ≡ e mod 2700 . -/ | | theorem colfree case {W x : Nat} hcf : colFree 8 W+1 % 225 x % 2700 = true | | hlt : c4 x < W : ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | have hv : 8 W+1 - 8 c4 x = 2 w+3 2 w+3 := by | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | have hmod := v mod eq W x Nat.le of lt hlt | | rw colFree at hcf | | have hnots : ∀ j : Nat, j j ≠ 8 W+1 - 8 c4 x := by | | apply beq land zero maskK1 all v := 8 W+1 - 8 c4 x | | have : Nat.mod 8 W+1 - 8 c4 x R1 = g225 8 W+1 % 225 x % 2700 := by | | simp only mod eqn, R1 | | rw hmod | | rw this | | exact hcf | | exact hnots 2 w+3 hv.symm | | | | theorem xtreeOK6 sound {W : Nat} h : xtreeOK6 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | intro w x heq | | have ht := t2 ge one w | | have hh : xtreeOK6 W = true := h | | simp only xtreeOK6, add eqn, mul eqn, sub eqn, pow eqn, mod eqn at hh | | rw Bool.and eq true, Bool.and eq true, Bool.and eq true at hh | | obtain ⟨hcap, ⟨hchk0, htree0⟩, hbr⟩ := hh | | rw Nat.blt eq at hcap | | set a := 8 W+1 % 225 with hadef | | set f := fla a with hfdef | | set CB := cbof a with hCBdef | | set xcap := newton newton 24 W with hxcapdef | | have hc4W : c4 x < W := by omega | | have hxle : x ≤ xcap := by | | by contra hgt | | have : c4 xcap + 1 ≤ c4 x := c4 mono by omega | | omega | | set e := x % 2700 with hedef | | set k := x / 2700 with hkdef | | have helt : e < 2700 := by omega | | have ha : a < 225 := Nat.mod lt by norm num | | -- k bound from the branch checks | | have hkb : k ≤ 1 := by | | cases hbW : Nat.ble c4 2700 W with | | | true = | | rw hbW, cond true, Bool.and eq true at hbr | | have h54 := hbr.1 | | rw Nat.blt eq at h54 | | have : x < 5400 := by | | by contra hgt | | have : c4 5400 ≤ c4 x := c4 mono by omega | | omega | | omega | | | false = | | rw hbW, cond false, Nat.blt eq at hbr | | have : x < 2700 := by | | by contra hgt | | have : c4 2700 ≤ c4 x := c4 mono by omega | | omega | | omega | | cases hcf : colFree a e with | | | true = exact colfree case hcf hc4W w heq | | | false = | | have hbs := comp spec a ha e helt hcf | | obtain ⟨i, hi0, hilt, hslot⟩ := bsA sound hbs | | have hilt2 : i < 2 ^ f := by | | rw hfdef | | simpa only pow eqn using hilt | | have hslot' : slotC CB i = e := by | | rw slotC, hCBdef | | exact hslot | | have hsort := sortA sound sortall spec a ha | | rw ← hfdef, ← hCBdef at hsort | | -- case on k | | cases hk0 : Nat.beq k 0 with | | | true = | | rw Nat.beq eq at hk0 | | -- k = 0 : covered by tree0 up to i0, or slot xcap | | set i0 := cutC CB xcap f+2 0 2^f with hi0def | | rcases Nat.lt or ge i i0 with hin | hout | | · have hleaf := allI sound htree0 i Nat.zero le by omega | | exact leafX6 sound hleaf e x hslot' by omega helt w heq | | · -- i ≥ i0 : slot i ≥ slot i0 xcap, contradiction with x ≤ xcap | | cases hq : Nat.beq i0 2^f with | | | true = | | rw Nat.beq eq at hq | | omega | | | false = | | rw hq, cond false, Nat.blt eq at hchk0 | | have : slotC CB i0 ≤ slotC CB i := hsort i0 i hout hilt2 | | omega | | | false = | | have hk1 : k = 1 := by | | have : ¬ k = 0 := by | | intro hcon | | rw hcon at hk0 | | simp at hk0 | | omega | | -- k = 1 : the branch must be in the true case | | have hbW : Nat.ble c4 2700 W = true := by | | cases hbW : Nat.ble c4 2700 W with | | | true = rfl | | | false = | | rw hbW, cond false, Nat.blt eq at hbr | | have : x < 2700 := by | | by contra hgt | | have : c4 2700 ≤ c4 x := c4 mono by omega | | omega | | omega | | rw hbW, cond true, Bool.and eq true, Bool.and eq true at hbr | | obtain ⟨h54, hchk1, htree1⟩ := hbr | | set i1 := cutC CB xcap - 2700 f+2 0 2^f with hi1def | | rcases Nat.lt or ge i i1 with hin | hout | | · have hleaf := allI sound htree1 i Nat.zero le by omega | | exact leafX6 sound hleaf e x hslot' by omega helt w heq | | · cases hq : Nat.beq i1 2^f with | | | true = | | rw Nat.beq eq at hq | | omega | | | false = | | rw hq, cond false, Nat.blt eq at hchk1 | | have : slotC CB i1 ≤ slotC CB i := hsort i1 i hout hilt2 | | omega | | | | theorem leafY6 sound {N r8 y : Nat} h : leafY6 N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp | | simp only leafY6, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK6 sound h w x this | | | | theorem ytree6 parts {N fy r8 : Nat} h1 : allB leafY6 N r8 fy 0 = true | | h2 : Nat.ble N Nat.add r8 c6 Nat.pow 2 fy = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY6 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | theorem leafZ6 sound {N fy z : Nat} h : leafZ6 N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ6, hb, cond false, Bool.and eq true at h | | exact ytree6 parts h.1 h.2 w x y heq | | | | theorem master6 {N fy fz : Nat} | | h : allB leafZ6 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ6 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | EOF | | tail -3 /tmp/v6d.log; sleep 45; tail -3 /tmp/v6d.log | | | | | | 213 --- TOOL bash --- | | real 0m50.997s | | user 0m20.466s | | sys 0m2.421s | | real 0m50.997s | | user 0m20.466s | | sys 0m2.421s | | | | | | 214 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && grep error /tmp/v6d.log | head -3; ls devlib/V6Defs.olean 2 /dev/null && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker6.lean -o devlib/Checker6.olean"' /tmp/c6.log 2 &1 & sleep 120; grep -n "error" /tmp/c6.log | head -6; tail -2 /tmp/c6.log | | | | | | 214 --- TOOL bash --- | | devlib/V6Defs.olean | | 1:Dev/Checker6.lean:201:37: error: Application type mismatch: The argument | | 9:Dev/Checker6.lean:234:37: error: Application type mismatch: The argument | | user 0m8.321s | | sys 0m1.870s | | | | | | 215 --- ASSISTANT --- | | bash | | | | sed -n 1,25p /tmp/c6.log; sed -n 197,204p /workspace/leanproject/Dev/Checker6.lean | | | | | | 215 --- TOOL bash --- | | Dev/Checker6.lean:201:37: error: Application type mismatch: The argument | | hslot' | | has type | | slotC CB i = e | | but is expected to have type | | e = slotC CB i | | in the application | | leafX6 sound hleaf e x hslot' | | Dev/Checker6.lean:234:37: error: Application type mismatch: The argument | | hslot' | | has type | | slotC CB i = e | | but is expected to have type | | e = slotC CB i | | in the application | | leafX6 sound hleaf e x hslot' | | | | real 0m14.723s | | user 0m8.321s | | sys 0m1.870s | | -- k = 0 : covered by tree0 up to i0, or slot xcap | | set i0 := cutC CB xcap f+2 0 2^f with hi0def | | rcases Nat.lt or ge i i0 with hin | hout | | · have hleaf := allI sound htree0 i Nat.zero le by omega | | exact leafX6 sound hleaf e x hslot' by omega helt w heq | | · -- i ≥ i0 : slot i ≥ slot i0 xcap, contradiction with x ≤ xcap | | cases hq : Nat.beq i0 2^f with | | | true = | | | | | | 216 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && sed -i 's/exact leafX6 sound hleaf e x hslot'"'"' by omega helt w heq/exact leafX6 sound hleaf e x hslot'"'"'.symm by omega helt w heq/' Dev/Checker6.lean && grep -n "hslot'.symm" Dev/Checker6.lean; nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker6.lean -o devlib/Checker6.olean"' /tmp/c6b.log 2 &1 & sleep 110; grep -n "error" /tmp/c6b.log | head -6; tail -2 /tmp/c6b.log; ls -la devlib/ | | | | | | 216 --- TOOL bash --- | | 201: exact leafX6 sound hleaf e x hslot'.symm by omega helt w heq | | 234: exact leafX6 sound hleaf e x hslot'.symm by omega helt w heq | | user 0m9.182s | | sys 0m2.156s | | total 5004 | | drwxr-xr-x. 2 root root 130 Aug 2 23:54 . | | drwxr-xr-x. 1 root root 62 Aug 2 22:21 .. | | -rw-r--r--. 1 root root 305912 Aug 2 22:25 Blobs.olean | | -rw-r--r--. 1 root root 1926944 Aug 2 22:22 Checker.olean | | -rw-r--r--. 1 root root 1155488 Aug 2 22:55 Checker5.olean | | -rw-r--r--. 1 root root 980784 Aug 2 23:54 Checker6.olean | | -rw-r--r--. 1 root root 573696 Aug 2 22:48 V5Defs.olean | | -rw-r--r--. 1 root root 163984 Aug 2 23:51 V6Defs.olean | | | | | | 217 --- ASSISTANT --- | | Checker6 compiled successfully, but I'm noticing a potential issue in the xtreeOK6 sound proof where the hin branch needs to properly handle the substitution of k values in the hxdef constraint—specifically when k equals 0, the expression should resolve correctly to match what leafX6 sound expects. | | | | The k := 0 case works out: omega can verify that x = 2700 0 + e simplifies to x = e using the definitional equality from the set bindings, and the compilation confirms this is sound. Next I need to verify the axioms of the new theorems, benchmark v6's performance, update the generator for v6, regenerate the test case for N=23343989, run the full compilation again expecting one error at z=27 , and then calibrate the timing. | | Checker6 compiled successfully. Now I'll benchmark v6 against v5 and verify the axioms. | | bash | | | | cd /workspace/leanproject && cat /tmp/ax6.lean <<'EOF' | | import Checker6 | | print axioms D.master6 | | print axioms D.xtreeOK6 sound | | EOF | | lake env sh -c 'LEAN PATH=$LEAN PATH:devlib lean /tmp/ax6.lean' 2 &1 | head -4 | | python3 - <<'EOF' | | import sys; sys.path.insert 0,'/tmp' | | import sim6, sim | | from sim import S, c8 | | N=5527622910037 | | z=0; r8=c8 z | | good= ; y=0 | | while len good <3 and y<512: | | s0=S.xleaf | | ok=all sim6.leafY6 N,r8,yy for yy in range y,y+16 | | if ok: good.append y,S.xleaf-s0 | | y+=16 | | print good | | EOF | | | | | | 217 --- TOOL bash --- | | 'D.master6' depends on axioms: propext, Classical.choice, Quot.sound | | 'D.xtreeOK6 sound' depends on axioms: propext, Classical.choice, Quot.sound | | 0, 12289 , 16, 9474 , 32, 11380 | | | | | | 218 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && cat Dev/BenchY6.lean <<'EOF' | | import Checker6 | | set option maxHeartbeats 40000000 | | set option Elab.async false | | namespace D | | theorem b60 : allB leafY6 5527622910037 0 4 0 = true := by decide +kernel | | theorem b61 : allB leafY6 5527622910037 0 4 16 = true := by decide +kernel | | theorem b62 : allB leafY6 5527622910037 0 4 32 = true := by decide +kernel | | end D | | EOF | | /tmp/measure2.sh Dev/BenchY6.lean "" | | | | | | 218 --- TOOL bash --- | | Dev/BenchY6.lean VmHWM 6782716 kB | | real 0m29.065s | | user 0m14.780s | | | | | | 219 --- ASSISTANT --- | | Looking at the v6 benchmark results, the per-leaf performance is actually worse than v5 despite the overall speedup—v6 is doing 289μs per leaf versus v5's 153μs, which is nearly double the cost. The total throughput only improved 1.24× when processing half as many leaves, so something in the implementation is significantly less efficient at the per-operation level. I'm starting to investigate what might be causing this regression. | | | | The main culprits seem to be the allI function's overhead: it's doing conditional branches and division operations at every node around 8-10 steps per node versus allB4's 3-4 per leaf , plus the recursive application pattern is passing two arguments to each inductive hypothesis, which adds extra beta reduction steps. The interval sizes look reasonable—v6 eliminated the useless leaves that v5 was generating, so the 33K leaves are actually doing useful work—but the cost per node in allI is eating up the gains. I'm thinking a hybrid approach might help: use power-of-2 subtrees for the bulk of the work to avoid the expensive branching and arithmetic at every step. So the real bottleneck for allI is the per-node overhead: each recursive step unfolds the motive, applies beta reductions, evaluates the condition and arithmetic operations—roughly 11-13 steps totaling around 55 microseconds per node. Since a binary tree has about twice as many nodes as leaves, that adds 110 microseconds per leaf on top of the leaf computation itself, bringing the total to 230-290 microseconds. The allB4 version was faster because it used 4-ary nodes with sharing, amortizing to only 1.5 steps per leaf. I could optimize allI similarly by either making it 4-ary or chunking the leaves. | | | | For small ranges, I'm unrolling the predicate check directly—something like p a && p a+1 && p a+2 && p a+3 with bounds guards—which would reduce the node count by 4× and cut the overhead to about 30 microseconds per leaf. The implementation uses nested conditionals to handle the cases where n ≤ 4, checking bounds with ble and equality with beq to dispatch to the right branch. | | | | Implementing the small-case logic... Looking at the performance projections—at 5.5e12 leaves I'm getting around 70 minutes, but scaling to 1.3e13 pushes it to 3.7 hours. I'm considering whether folding the k=0 and k=1 trees together would help, but that doesn't actually save work per leaf. The real opportunity is trimming the leaf computation itself—currently running 90-130μs per leaf with operations like slot calculations, comparisons, and the square test taking up most of the cycles. I'm thinking about dropping the sentinel guard to reduce overhead. | | | | The key insight is that within the prefix range 0, i0 , sentinels can't actually appear when the capacity is below 2700, and since the sentinel value 4095 always exceeds the limit, the guard exclusion never triggers for tree-covered indices. The leaf definition's guard is really just for kernel-eval safety—without it, a sentinel leaf would compute x=2700k+4095, but the comparison x A8 would set v=0, which exits via the ble v 1 condition anyway. So removing the guard saves 2 steps without breaking soundness, since the sentinel case still exits safely through the same path. | | | | Looking at the overall cost, a single leaf runs about 20-24 steps plus the base-case chain overhead of roughly 2.5 steps and internal logic around 4 steps, totaling somewhere in the 28-30 step range or about 135 microseconds. That's still slower than hoped. If I accept roughly 175 microseconds per leaf and assume N0 stays under 8×10^12 around 37 million leaves , the total runtime would be about 1.9 hours, though if N0 climbs to 1.3×10^13 it stretches to 3.7 hours, which is risky. | | | | There's a more aggressive alternative: reduce the number of full leaves by applying additional modulus masks on the slots—specifically filtering for values that are quadratic residues modulo 225, then adding a second filter modulo 539 to further narrow the candidate set. | | | | Looking at the actual numbers, most full leaves get rejected right after the K2 test, so the secondary chain isn't the bottleneck—the real cost is computing x, t, c, and v for each leaf. To skip leaves entirely I'd need a slot-level pre-filter, but since v mod 539 depends on both k and W rather than just the slot, that approach hits a dead end. | | | | Now I'm exploring whether I can store precomputed 8·c4 e values to reduce the leaf arithmetic. The extraction would replace several multiplication and subtraction steps, but storing these values for all e-slots requires around 44 bits per entry, and including k=1 variants pushes it to 91-bit slots. That balloons the blob to roughly 1.85MB in binary format, which is manageable at the megabyte scale. | | | | The key insight is that if I have the c4-value precomputed, I don't need x at all—I can extract c8v directly from the blob, compute v := A8 − 8·c8v with just a subtraction, and skip the entire x and t computation. The leaf operations then become extract around 3 steps , subtraction 1 step , and the squareness test 6-10 steps , totaling roughly 20 steps or 90 microseconds. | | | | For the cut operation, instead of computing xcap and using Newton's method, I can sort the c4-values directly and find the boundary where c4 x W, which means v would underflow. This eliminates the need for Newton iteration entirely—I just find the first index where the c4-value exceeds the threshold and know that all slots beyond that have no solution. | | | | Now I'm working through the soundness and completeness arguments: I need to prove that the c4-blob is sorted per class per k, and then connect the c4-value at each slot back to the original c4 function by verifying that c4val a,i,k equals c4 2700k + slot a,i . 11 seconds of runtime overhead seems acceptable. The key insight is that we can precompute and store the c4 values in a blob, which means at runtime we only need to extract from that blob rather than recompute. The SEL blob stays necessary for the soundness verification path—specifically for the binary search and constraint checking—but the leaf verification itself just pulls the precomputed c4 value and validates it matches the expected computation. | | | | Now I'm working through the C4 blob layout: I need two separate blobs for the two k-values, storing 8·c4 e rather than raw c4 e to keep the numbers manageable. For k=0, that's around 1.77e13 which fits in 45 bits, and for k=1 it's 2.83e14 fitting in 48 bits. I'll use sentinel values for padding the slots to mark boundaries. | | | | Actually, reconsidering the approach: instead of storing 8·c4, I should store just c4 directly and use a unified 46-bit slot size across both blobs. This keeps c4 2699 under 2^42 and c4 5399 under 2^46, with the sentinel value at 2^46−1 exceeding any threshold I'd need for comparisons. Two blobs of 163K slots each at 46 bits per slot gives me roughly 940KB per blob, totaling about 4.6MB for the decimal representation. | | | | The file size is chunky at around 5.5MB, but the kernel handles it fine. Converting the 2.3M-digit decimal literals to GMP uses subquadratic parsing, so that's acceptable. For per-class extraction, I'm pulling pairs from the big blobs with shifts and masks—roughly 100-200 microseconds per blob extraction across 55K pairs and two blobs, which should complete in 11-22 seconds. The tricky part is cutting on the value blob: I need to find the first index where the value exceeds the threshold W, which requires the slot values to be sorted per class. | | | | The key insight is that the slot values are already sorted in ascending order, so the class values inherit that monotonicity through the c4 function. I don't need a separate sort lemma—the sortedness follows from the existing SORTALL property combined with the monotonicity of c4 and the slot ordering. For the boundary check, I verify that values at or beyond the cutoff index are indeed greater than W, which holds because the value sorting is provable from the linked structure and monotonicity properties. | | | | For k=1 trees, the branching logic simplifies significantly: if the threshold W is less than c4 2700 , then all values in that subtree exceed W anyway, so the cut automatically returns an empty tree without needing an explicit branch. For k≥2, I still need the static boundary check at c4 5400 . On the leaf side, I'm extracting the value from the blob and then computing a derived value using subtraction and multiplication operations. | | | | The sentinel check handles the edge case where the value is maximal 2^46−1 , which would make the derived value zero and trigger an early exit. Running through the full operation—extraction, value computation, guard check, and the core test—takes roughly 16-20 steps per leaf, translating to about 75-90 microseconds per leaf plus overhead for internal nodes, bringing the total to roughly 110-145 microseconds per leaf. That's more than a 2× improvement over the current 289 microseconds. | | | | Eliminating Newton's method entirely from the tree structure also simplifies the implementation considerably. The main cost is generating new blob data and deciding on kernel chunk boundaries, plus updating the tree proofs, but the performance gain makes it worthwhile. | | | | Now looking at the leaf count and timing: at 1.3e13 with 76 million leaves, the same 24M/76M split from v6 would still take around 120 microseconds per leaf, landing at roughly 48 minutes for the full computation. Adding a base-4 optimization to the internal node handling could push that down to 40 minutes. Since the internal node optimization is independent, I should fold that into v7 as well. | | | | The plan is to implement v7 with value blobs, no Newton's method, and the internal node base-2 unroll. The first step involves extending the blob generation to create the new 46-bit slot structures with the sentinel value, using the same offset calculation pattern as the existing blob format. | | | | For the offset storage, I need to add a second offset blob since the current one stores 12-bit slot offsets. For 46-bit slots, I can calculate the bit offset as 46 times the cumulative slot count. Rather than doing division, I'll create a separate offset blob that directly stores these 46-bit cumulative values, which only needs 24 bits per entry since 46 times 163K is around 7.5 million. Then I'll write the Python simulation and validation for v7. | | | | Now I'm defining the V7Defs.lean file with the constants and helper functions for C4B0, C4B1, and the new OFFB46 blob, along with the tree validation predicates. For the LINKC specification, I need to handle the sentinel case where a slot value of 4095 should map to the maximum value instead of trying to index into the compressed data, so I'll formulate it as a conditional: either the slot is valid and maps to the compressed values, or it's a sentinel. | | | | For soundness, I'm deriving from the sorted slot array that if a slot value is less than 2700, the LINKC statement correctly produces the corresponding c4 values, and then I need to establish value-sortedness by showing that the compressed values preserve the ordering from the sorted slots. Verifying the boundary conditions for each k value with a simple less-than check, then moving on to adapt the Checker7 proofs and generate version 7 with a full test run. I'm also refactoring the leaf function to handle the two blob variants through partial application. Defining a recursive function that checks a property across a range of natural numbers, with base cases for n=0, 1, 2 and a divide-and-conquer approach for larger values, then verifying its correctness through induction on those base cases. Completing the validity checks for the tree structure, then defining a separate cutV function that works with 46-bit extracts instead of hardcoding 12-bit widths like cutC does. For the soundness proof, I'm verifying that when the condition holds, the extracted value stays within bounds—specifically that x divides into quotient k ≤ 1 and remainder e < 2700. I'm verifying the value-monotonicity constraint by checking that the slot values are properly ordered, which forces the encoded values to satisfy the inequality W < V0 i0 ≤ c4 x , contradicting the assumption. The same reasoning applies for the k=1 case with V1 and x = 2700+e. Now I'm moving on to define the linkG structure for deciding the link configuration. Defining extraction functions... | | | | Now I need to generate the blob data structures with the constants and then implement the simulator, verification definitions, and checker for version 7, while keeping version 6 as a backup option. | | V6 is functional but has high node overhead, so I'm moving to v7 which will store precomputed c4-values in blobs to eliminate arithmetic operations and use a base-2-unrolled interval tree. I'll start by extending the blobs. | | bash | | | | cd /tmp && python3 - <<'EOF' | | import pickle, sys | | sys.set int max str digits 4000000 | | from math import comb | | from sim import K1 | | def c4 x : return x x+1 x+2 x+3 //24 | | def sqbit m : return K1 m &1 | | def g225 a,e : return a+1800 - 8 c4 e %225 % 225 | | S46= 1<<46 -1 | | FLB=0; OFFB=0; SELB=0; OFFB46=0; C4B0=0; C4B1=0 | | off=0; off46=0 | | for a in range 225 : | | allowed= e for e in range 2700 if sqbit g225 a,e ==1 | | L=len allowed | | f=0 | | while 1<<f <max L,1 : f+=1 | | S=1<<f | | slots=allowed+ 4095 S-L | | assert off< 1<<24 and off46< 1<<24 | | OFFB |= off<< 24 a ; OFFB46 |= off46<< 24 a ; FLB |= f<< 4 a | | for i,s in enumerate slots : | | SELB |= s<< off+12 i | | if s =2700: | | v0=S46; v1=S46 | | else: | | v0=c4 s ; v1=c4 2700+s | | assert v0<S46 and v1<S46 | | C4B0 |= v0<< off46+46 i | | C4B1 |= v1<< off46+46 i | | off += 12 S; off46 += 46 S | | pickle.dump FLB,OFFB,SELB,OFFB46,C4B0,C4B1 ,open "/tmp/blobs7.pkl","wb" | | print "total slots bits12",off,"bits46",off46, "C4B0 digits",len str C4B0 | | sanity: consistency with old pickle | | oF,oO,oS=pickle.load open "/tmp/blobs.pkl","rb" | | print "consistent:",oF==FLB and oO==OFFB and oS==SELB | | EOF | | | | | | 219 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 220 --- ASSISTANT --- | | The timeout is happening because the bit-shifting operation with growing big integers is quadratic in complexity — 163K iterations each shifting into multi-megabit numbers. I need a more efficient approach: instead of accumulating everything into one massive integer, I should collect the values and bit positions separately, then assemble them by building per-class integers first and combining them through chunks to avoid the expensive large-number arithmetic. | | bash | | | | cd /tmp && python3 - <<'EOF' | | import pickle, sys | | sys.set int max str digits 4000000 | | from sim import K1 | | def c4 x : return x x+1 x+2 x+3 //24 | | def sqbit m : return K1 m &1 | | def g225 a,e : return a+1800 - 8 c4 e %225 % 225 | | S46= 1<<46 -1 | | FLB=0; OFFB=0; OFFB46=0 | | sel cls= ; v0 cls= ; v1 cls= ; fs= | | off=0; off46=0 | | for a in range 225 : | | allowed= e for e in range 2700 if sqbit g225 a,e ==1 | | L=len allowed ; f=0 | | while 1<<f <max L,1 : f+=1 | | S=1<<f | | slots=allowed+ 4095 S-L | | assert off< 1<<24 and off46< 1<<24 | | OFFB |= off<< 24 a ; OFFB46 |= off46<< 24 a ; FLB |= f<< 4 a | | si=0; w0=0; w1=0 | | for i,s in enumerate slots : | | si |= s<< 12 i | | if s =2700: v0=S46; v1=S46 | | else: | | v0=c4 s ; v1=c4 2700+s ; assert v0<S46 and v1<S46 | | w0 |= v0<< 46 i ; w1 |= v1<< 46 i | | sel cls.append si,off ; v0 cls.append w0,off46 ; v1 cls.append w1,off46 | | off += 12 S; off46 += 46 S | | def join cls : | | items= v,o for v,o in cls | | while len items 1: | | nxt= | | for j in range 0,len items ,2 : | | if j+1<len items : | | v1,o1 , v2,o2 =items j ,items j+1 | | nxt.append v1 | v2<< o2-o1 , o1 | | else: nxt.append items j | | items=nxt | | return items 0 0 | | SELB=join sel cls ; C4B0=join v0 cls ; C4B1=join v1 cls | | pickle.dump FLB,OFFB,SELB,OFFB46,C4B0,C4B1 ,open "/tmp/blobs7.pkl","wb" | | oF,oO,oS=pickle.load open "/tmp/blobs.pkl","rb" | | print "consistent:",oF==FLB and oO==OFFB and oS==SELB, "bits46",off46 | | EOF | | | | | | 220 --- TOOL bash --- | | consistent: True bits46 7868024 | | | | | | 221 --- ASSISTANT --- | | Blobs7 are built and match the previous versions, with C4B0 and C4B1 each at about 7.87 megabits or roughly 983 kilobytes in binary form. The total file size should come to around 5.5 megabytes, which is manageable. Next I'm writing sim7 to align with the planned definitions, then cross-referencing it against sim5 and sim6 before running the checker. | | bash | | | | cat /tmp/sim7.py <<'EOF' | | v7: c4-value blobs; no newton/xcap; exact mirror of Lean defs | | import pickle | | from sim import K2,K3,K4,R2,R3,R4, c4,c6,c8, S, bracketOK | | FLB,OFFB,SELB,OFFB46,C4B0,C4B1=pickle.load open "/tmp/blobs7.pkl","rb" | | S46= 1<<46 -1 | | C5400=c4 5400 | | def fla a : return FLB 4 a &15 | | def off46 a : return OFFB46 24 a &16777215 | | def cbv0 a : return C4B0 off46 a & 1<< 46 1<<fla a -1 | | def cbv1 a : return C4B1 off46 a & 1<< 46 1<<fla a -1 | | def slotV CBV,i : return CBV 46 i &S46 | | | | def cutV CBV,lim,fuel,lo,hi : | | while fuel 0: | | if hi<=lo: return lo | | mid= lo+hi //2 | | if slotV CBV,mid <=lim: lo=mid+1 | | else: hi=mid | | fuel-=1 | | return lo | | | | def sqT v : | | S.sq2+=1 | | if K2 v%R2 &1==0: return True | | if K3 v%R3 &1==0: return True | | if K4 v%R4 &1==0: return True | | return bracketOK v | | | | def leafX7 A8,CBV,i : | | S.xleaf+=1 | | v=A8-8 slotV CBV,i | | if v<0: v=0 | | if v<=1: return True | | return sqT v | | | | def allI2 p,fuel,a,n : | | if fuel<=0: return n==0 | | for i in range a,a+n : | | if not p i : return False | | return True | | | | def xtreeOK7 W : | | S.pairs+=1 | | A8=8 W+1; a=A8%225; f=fla a | | V0=cbv0 a ; V1=cbv1 a | | i0=cutV V0,W,f+2,0,1<<f | | i1=cutV V1,W,f+2,0,1<<f | | if not i0==1<<f or W<slotV V0,i0 : return False | | if not i1==1<<f or W<slotV V1,i1 : return False | | if not W<C5400: return False | | if not allI2 lambda i: leafX7 A8,V0,i ,13,0,i0 : return False | | if not allI2 lambda i: leafX7 A8,V1,i ,13,0,i1 : return False | | return True | | | | def leafY7 N,r8,y : | | b=r8+c6 y | | if N<=b: return True | | return xtreeOK7 N-b | | | | def leafZ7 N,fy,z : | | r8=c8 z | | if N<=r8: return True | | if not N<=r8+c6 2 fy : return False | | return all leafY7 N,r8,y for y in range 2 fy | | | | def master7 N,fy=9,fz=8 : | | if not N<=c8 2 fz : return False | | return all leafZ7 N,fy,z for z in range 2 fz | | | | def count pair W : | | a= 8 W+1 %225; f=fla a | | return cutV cbv0 a ,W,f+2,0,1<<f +cutV cbv1 a ,W,f+2,0,1<<f | | | | LINKC check | | def linkA a : | | f=fla a ; V0=cbv0 a ; V1=cbv1 a | | off= OFFB 24 a &16777215 | | CB= SELB off & 1<< 12 1<<f -1 | | for i in range 1<<f : | | s= CB 12 i &4095 | | if s =2700: | | if not slotV V0,i ==S46 and slotV V1,i ==S46 : return False | | else: | | if not slotV V0,i ==c4 s and slotV V1,i ==c4 2700+s : return False | | return True | | | | if name ==" main ": | | import sys | | if sys.argv 1 =="check": | | assert all linkA a for a in range 225 ; print "LINKC ok" | | import random, sim5 | | random.seed 3 ; bad=0 | | for t in range 4000 : | | W=random.randint 1,6 10 12 | | if sim5.xtreeOK5 W =xtreeOK7 W : bad+=1; print "MISMATCH",W | | print "xtree cross-check mismatches",bad | | else: | | N=int sys.argv 1 ; print N, master7 N ; print "pairs",S.pairs,"xleaf",S.xleaf | | EOF | | cd /tmp && python3 sim7.py check | | | | | | 221 --- TOOL bash --- | | LINKC ok | | xtree cross-check mismatches 0 | | | | | | 222 --- ASSISTANT --- | | Now that sim7 is validated, I need to write V7Defs.lean with the new blob literals and then Checker7.lean. For the blob literals, I'm creating a Blobs7.lean file that defines OFFB46, C4B0, and C4B1, while the existing blob definitions like FLB, OFFB, and SELB stay in Blobs.lean. | | bash | | | | cd /workspace/leanproject && python3 - <<'EOF' | | import pickle,sys | | sys.set int max str digits 4000000 | | FLB,OFFB,SELB,OFFB46,C4B0,C4B1=pickle.load open "/tmp/blobs7.pkl","rb" | | with open "Dev/Blobs7.lean","w" as f: | | f.write "import Checker\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def OFFB46 : Nat := %d\n" % OFFB46 | | f.write "def C4B0 : Nat := %d\n" % C4B0 | | f.write "def C4B1 : Nat := %d\n" % C4B1 | | f.write "end D\n" | | print "written" | | EOF | | nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Blobs7.lean -o devlib/Blobs7.olean"' /tmp/b7.log 2 &1 & echo bg | | | | | | 222 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 223 --- ASSISTANT --- | | bash | | | | ls -la /workspace/leanproject/Dev/Blobs7.lean 2 /dev/null; tail -2 /tmp/b7.log 2 /dev/null; ps -C lean -o pid,rss,etime | tail -2 | | | | | | 223 --- TOOL bash --- | | -rw-r--r--. 1 root root 2370251 Aug 3 00:10 /workspace/leanproject/Dev/Blobs7.lean | | 5027 0 03:00:14 | | 7114 0 02:13:24 | | | | | | 224 --- ASSISTANT --- | | The Blobs7.lean file is only 2.37MB when it should be around 4.8MB since it contains two 2.4-million-digit numbers — the Python process got killed by the 300-second timeout while writing those massive decimal strings, since converting integers to strings at that scale is computationally expensive. The nohup compilation never even started because the command timed out before reaching it. | | | | I need to rewrite this with a faster, more robust approach and run it in the background to avoid these timeout issues. | | bash | | | | cd /workspace/leanproject && nohup python3 - /tmp/b7gen.log 2 &1 <<'EOF' & | | import pickle,sys | | sys.set int max str digits 8000000 | | FLB,OFFB,SELB,OFFB46,C4B0,C4B1=pickle.load open "/tmp/blobs7.pkl","rb" | | with open "Dev/Blobs7.lean","w" as f: | | f.write "import Checker\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def OFFB46 : Nat := %d\n" % OFFB46 | | f.write "def C4B0 : Nat := %d\n" % C4B0 | | f.write "def C4B1 : Nat := %d\n" % C4B1 | | f.write "end D\n" | | print "written ok" | | EOF | | sleep 100; cat /tmp/b7gen.log; ls -la Dev/Blobs7.lean | | | | | | 224 --- TOOL bash --- | | -rw-r--r--. 1 root root 0 Aug 3 00:12 Dev/Blobs7.lean | | | | | | 225 --- ASSISTANT --- | | bash | | | | sleep 120; cat /tmp/b7gen.log; ls -la /workspace/leanproject/Dev/Blobs7.lean | | | | | | 225 --- TOOL bash --- | | -rw-r--r--. 1 root root 2370251 Aug 3 00:15 /workspace/leanproject/Dev/Blobs7.lean | | | | | | 226 --- ASSISTANT --- | | I'm working through the performance implications of converting large integers to strings in Python. The conversion process is computationally expensive—with integers around 7.9 million bits roughly 2.37 million digits , the operation becomes quadratic in complexity, which explains why there's a practical limit around 4300 digits before the algorithm becomes prohibitively slow. | | | | I'm considering switching to hexadecimal representation instead, since converting to hex is linear time and would reduce the file size from 2.37 million decimal characters down to about 1.97 million hex characters. Lean supports hex literals directly with the 0x prefix, so this could be a much more efficient approach. I need to check what Python version I'm running and whether the current conversion process has finished, then decide whether to continue waiting or switch strategies. | | bash | | | | python3 --version; sleep 60; cat /tmp/b7gen.log; ls -la /workspace/leanproject/Dev/Blobs7.lean | | | | | | 226 --- TOOL bash --- | | Python 3.11.2 | | -rw-r--r--. 1 root root 2370251 Aug 3 00:15 /workspace/leanproject/Dev/Blobs7.lean | | | | | | 227 --- ASSISTANT --- | | bash | | | | pkill -f "python3 -" ; cd /workspace/leanproject && python3 - <<'EOF' | | import pickle | | FLB,OFFB,SELB,OFFB46,C4B0,C4B1=pickle.load open "/tmp/blobs7.pkl","rb" | | with open "Dev/Blobs7.lean","w" as f: | | f.write "import Checker\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def OFFB46 : Nat := %d\n" % OFFB46 | | f.write "def C4B0 : Nat := 0x%x\n" % C4B0 | | f.write "def C4B1 : Nat := 0x%x\n" % C4B1 | | f.write "end D\n" | | print "written ok" | | EOF | | ls -la Dev/Blobs7.lean; nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Blobs7.lean -o devlib/Blobs7.olean"' /tmp/b7.log 2 &1 & echo bg | | | | | | 227 --- TOOL bash --- | | <stdout </stdout | | <stderr Terminated | | </stderr | | <returncode 143</returncode | | | | 228 --- ASSISTANT --- | | Oh no, the pkill command matched my own heredoc python process too since "python3 -" is part of the pattern. I need to avoid pkill and instead check if the background process is still running before proceeding, since it might still be writing output and could cause conflicts. | | bash | | | | ps aux | grep -c "python3 -$"; cd /workspace/leanproject && python3 - <<'EOF' | | import pickle | | FLB,OFFB,SELB,OFFB46,C4B0,C4B1=pickle.load open "/tmp/blobs7.pkl","rb" | | with open "Dev/Blobs7.lean","w" as f: | | f.write "import Checker\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def OFFB46 : Nat := %d\n" % OFFB46 | | f.write "def C4B0 : Nat := 0x%x\n" % C4B0 | | f.write "def C4B1 : Nat := 0x%x\n" % C4B1 | | f.write "end D\n" | | print "written ok" | | EOF | | ls -la Dev/Blobs7.lean | | | | | | 228 --- TOOL bash --- | | 0 | | written ok | | -rw-r--r--. 1 root root 3935780 Aug 3 00:17 Dev/Blobs7.lean | | | | | | 229 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && nohup bash -c 'time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Blobs7.lean -o devlib/Blobs7.olean"' /tmp/b7.log 2 &1 & | | cat Dev/V7Defs.lean <<'EOF' | | import Checker5 | | import Blobs7 | | set option linter.style.moduleDocstring false | | set option maxHeartbeats 4000000 | | set option Elab.async false | | | | /- v7: precomputed c4-value blobs; prefix-pruned enumeration without Newton. -/ | | | | namespace D | | | | def slotC CB i : Nat : Nat := Nat.land Nat.shiftRight CB Nat.mul 12 i 4095 | | | | def slotV CBV i : Nat : Nat := Nat.land Nat.shiftRight CBV Nat.mul 46 i 70368744177663 | | | | def off46 a : Nat : Nat := Nat.land Nat.shiftRight OFFB46 Nat.mul 24 a 16777215 | | | | def cbv0 a : Nat : Nat := | | Nat.land Nat.shiftRight C4B0 off46 a | | Nat.sub Nat.pow 2 Nat.mul 46 Nat.pow 2 fla a 1 | | | | def cbv1 a : Nat : Nat := | | Nat.land Nat.shiftRight C4B1 off46 a | | Nat.sub Nat.pow 2 Nat.mul 46 Nat.pow 2 fla a 1 | | | | /- sortedness of the 12-bit slot lists -/ | | | | def sortA CB f : Nat : Bool := | | allBH fun i = cond Nat.ble Nat.pow 2 f Nat.add i 1 true | | Nat.ble slotC CB i slotC CB Nat.add i 1 f 0 | | | | def sortG : Nat → Bool := fun a = cond Nat.ble 225 a true sortA cbof a fla a | | | | def SORTALL : Bool := allB sortG 8 0 | | | | theorem sortT 0 : allB sortG 6 0 = true := by decide +kernel | | theorem sortT 1 : allB sortG 6 64 = true := by decide +kernel | | theorem sortT 2 : allB sortG 6 128 = true := by decide +kernel | | theorem sortT 3 : allB sortG 6 192 = true := by decide +kernel | | | | theorem sortL 0 : allB sortG 7 0 = true := by | | rw show 7:Nat = 6+1 from rfl, allB succ | | rw show 0:Nat + 2^6 = 64 by norm num | | rw sortT 0, sortT 1 | | rfl | | theorem sortL 1 : allB sortG 7 128 = true := by | | rw show 7:Nat = 6+1 from rfl, allB succ | | rw show 128:Nat + 2^6 = 192 by norm num | | rw sortT 2, sortT 3 | | rfl | | theorem sortall true : SORTALL = true := by | | rw SORTALL, show 8:Nat = 7+1 from rfl, allB succ | | rw show 0:Nat + 2^7 = 128 by norm num | | rw sortL 0, sortL 1 | | rfl | | | | /- link between 12-bit slots and 46-bit value slots -/ | | | | def linkA a : Nat : Bool := | | let f := fla a | | let CB := cbof a | | let V0 := cbv0 a | | let V1 := cbv1 a | | allBH fun i = | | let s := slotC CB i | | cond Nat.ble 2700 s | | Nat.beq slotV V0 i 70368744177663 .and Nat.beq slotV V1 i 70368744177663 | | Nat.beq slotV V0 i c4 s .and Nat.beq slotV V1 i c4 Nat.add 2700 s f 0 | | | | def linkG : Nat → Bool := fun a = cond Nat.ble 225 a true linkA a | | | | def LINKALL : Bool := allB linkG 8 0 | | | | theorem linkT 0 : allB linkG 6 0 = true := by decide +kernel | | theorem linkT 1 : allB linkG 6 64 = true := by decide +kernel | | theorem linkT 2 : allB linkG 6 128 = true := by decide +kernel | | theorem linkT 3 : allB linkG 6 192 = true := by decide +kernel | | | | theorem linkL 0 : allB linkG 7 0 = true := by | | rw show 7:Nat = 6+1 from rfl, allB succ | | rw show 0:Nat + 2^6 = 64 by norm num | | rw linkT 0, linkT 1 | | rfl | | theorem linkL 1 : allB linkG 7 128 = true := by | | rw show 7:Nat = 6+1 from rfl, allB succ | | rw show 128:Nat + 2^6 = 192 by norm num | | rw linkT 2, linkT 3 | | rfl | | theorem linkall true : LINKALL = true := by | | rw LINKALL, show 8:Nat = 7+1 from rfl, allB succ | | rw show 0:Nat + 2^7 = 128 by norm num | | rw linkL 0, linkL 1 | | rfl | | | | /- runtime search and interval tree -/ | | | | def cutV CBV lim : Nat : Nat → Nat → Nat → Nat := fun fuel = | | Nat.rec motive := fun = Nat → Nat → Nat | | fun lo = lo | | fun ih lo hi = | | cond Nat.ble hi lo lo | | let mid := Nat.div Nat.add lo hi 2 | | cond Nat.ble slotV CBV mid lim ih Nat.add mid 1 hi ih lo mid | | fuel | | | | def allI2 p : Nat → Bool : Nat → Nat → Nat → Bool := fun fuel = | | Nat.rec motive := fun = Nat → Nat → Bool | | fun n = Nat.beq n 0 | | fun ih a n = | | cond Nat.ble n 2 | | cond Nat.beq n 0 true | | cond Nat.beq n 1 p a p a .and p Nat.add a 1 | | let h := Nat.div n 2 | | ih a h .and ih Nat.add a h Nat.sub n h | | fuel | | | | def leafX7 A8 CBV i : Nat : Bool := | | let v := Nat.sub A8 Nat.mul 8 slotV CBV i | | cond Nat.ble v 1 true sqTest2 v | | | | def xtreeOK7 W : Nat : Bool := | | let A8 := Nat.add Nat.mul 8 W 1 | | let a := Nat.mod A8 225 | | let f := fla a | | let V0 := cbv0 a | | let V1 := cbv1 a | | let i0 := cutV V0 W Nat.add f 2 0 Nat.pow 2 f | | let i1 := cutV V1 W Nat.add f 2 0 Nat.pow 2 f | | cond Nat.beq i0 Nat.pow 2 f true Nat.blt W slotV V0 i0 .and | | cond Nat.beq i1 Nat.pow 2 f true Nat.blt W slotV V1 i1 .and | | Nat.blt W c4 5400 .and | | allI2 leafX7 A8 V0 13 0 i0 .and allI2 leafX7 A8 V1 13 0 i1 | | | | def leafY7 N r8 y : Nat : Bool := | | let b := Nat.add r8 c6 y | | cond Nat.ble N b true xtreeOK7 Nat.sub N b | | | | def leafZ7 N fy z : Nat : Bool := | | let r8 := c8 z | | cond Nat.ble N r8 true | | allB leafY7 N r8 fy 0 .and Nat.ble N Nat.add r8 c6 Nat.pow 2 fy | | | | end D | | EOF | | echo written; sleep 60; tail -2 /tmp/b7.log | | | | | | 229 --- TOOL bash --- | | written | | | | | | 230 --- ASSISTANT --- | | bash | | | | sleep 120; tail -3 /tmp/b7.log; ls -la /workspace/leanproject/devlib/Blobs7.olean 2 /dev/null; tail -1 /tmp/scan99c.err | | | | | | 230 --- TOOL bash --- | | block 6/34 done marks=168695294650 zeros=0 | | | | | | 231 --- ASSISTANT --- | | bash | | | | sleep 120; tail -3 /tmp/b7.log; ls -la /workspace/leanproject/devlib/Blobs7.olean 2 /dev/null; ps -C lean -o pid,rss,etime | tail -2 | | | | | | 231 --- TOOL bash --- | | 7114 0 02:24:25 | | 11933 6394860 05:08 | | | | | | 232 --- ASSISTANT --- | | Blobs7 is still compiling with high memory usage while parsing large literals, and the scan is progressing through block 6 of 34 without encountering zeros. In the meantime, I'm working on the Checker7.lean proofs, adapting from the previous version with sortall spec and sortA sound carrying over unchanged, while adding new specifications like linkall spec to verify the link operation and starting on linkA sound. | | | | Now I'm working through the proof of linkA sound, which needs to extract per-index facts from the condition that linkA returns true — specifically, for each index i, I need to establish what values slotV holds based on whether slotC is below the 2700 threshold. The tricky part is handling the let-binding in the lambda body when applying allBH sound, since beta-reduction produces a let-expression that I need to simplify by rewriting with the concrete slot value, then using simp to handle zeta-reduction and extract the resulting conditional. | | | | I also need to set up allI2 sound for the base cases where n is 0, 1, or 2, and then prove leafX7 sound, which establishes that for a given slot value, the weighted sum can never equal W. Handling the case structure where I extract the bounds and tree conditions, then work through the color-freedom constraint. I'm running into a potential name clash if Checker7 imports both V6 and V7 definitions since sortall and related functions are defined in both places, so I need to figure out how to reuse the existing lemmas without duplication. The issue is that if Checker7 imports both Checker6 and V7Defs, there's a namespace collision since V7Defs redefines sortA and other sort-related definitions that already exist in V6Defs. I could either duplicate colfree case in Checker7 with a new name, or have V7Defs import V6Defs instead to avoid the redefinition conflict—since V6Defs already has the SORTALL and sortA definitions that v7 actually needs. Checker7 will pull in the proofs for the link-based definitions and the leaf/tree structures, while Blobs7 stays as-is since it only imports Checker. For the final generated file, I need to extract from V6Defs the slot and sort definitions plus sortall true, and from Checker6 the relevant soundness proofs, skipping the leaf/tree components. Let me update V7Defs to reflect this cleaner separation. | | While Blobs7 compiles, restructure V7Defs to reuse v6's sortedness machinery: | | bash | | | | cd /workspace/leanproject && python3 - <<'PYEOF' | | c=open 'Dev/V7Defs.lean' .read | | c=c.replace """import Checker5 | | import Blobs7""","""import Checker6 | | import Blobs7""" | | remove duplicated slotC + sort block | | i1=c.index "def slotC" | | i2=c.index "def slotV" | | c=c :i1 +c i2: | | i1=c.index "/- sortedness of the 12-bit slot lists -/" | | i2=c.index "/- link between 12-bit slots and 46-bit value slots -/" | | c=c :i1 +c i2: | | open 'Dev/V7Defs.lean','w' .write c | | print "ok" | | PYEOF | | grep -n "def \|theorem " Dev/V7Defs.lean | head -30; tail -2 /tmp/b7.log | | | | | | 232 --- TOOL bash --- | | ok | | 11:def slotV CBV i : Nat : Nat := Nat.land Nat.shiftRight CBV Nat.mul 46 i 70368744177663 | | 13:def off46 a : Nat : Nat := Nat.land Nat.shiftRight OFFB46 Nat.mul 24 a 16777215 | | 15:def cbv0 a : Nat : Nat := | | 19:def cbv1 a : Nat : Nat := | | 25:def linkA a : Nat : Bool := | | 36:def linkG : Nat → Bool := fun a = cond Nat.ble 225 a true linkA a | | 38:def LINKALL : Bool := allB linkG 8 0 | | 40:theorem linkT 0 : allB linkG 6 0 = true := by decide +kernel | | 41:theorem linkT 1 : allB linkG 6 64 = true := by decide +kernel | | 42:theorem linkT 2 : allB linkG 6 128 = true := by decide +kernel | | 43:theorem linkT 3 : allB linkG 6 192 = true := by decide +kernel | | 45:theorem linkL 0 : allB linkG 7 0 = true := by | | 50:theorem linkL 1 : allB linkG 7 128 = true := by | | 55:theorem linkall true : LINKALL = true := by | | 63:def cutV CBV lim : Nat : Nat → Nat → Nat → Nat := fun fuel = | | 72:def allI2 p : Nat → Bool : Nat → Nat → Nat → Bool := fun fuel = | | 83:def leafX7 A8 CBV i : Nat : Bool := | | 87:def xtreeOK7 W : Nat : Bool := | | 100:def leafY7 N r8 y : Nat : Bool := | | 104:def leafZ7 N fy z : Nat : Bool := | | | | | | 233 --- ASSISTANT --- | | Now write Checker7.lean with the proofs: | | bash | | | | cd /workspace/leanproject && cat Dev/Checker7.lean <<'EOF' | | import V7Defs | | set option linter.style.moduleDocstring false | | set option maxHeartbeats 1000000 | | | | namespace D | | | | theorem linkall spec : ∀ a, a < 225 → linkA a = true := by | | intro a ha | | have h := allB sound 0 linkall true a Nat.zero le by omega | | simp only linkG at h | | have hble : Nat.ble 225 a = false := by | | cases hb : Nat.ble 225 a with | | | true = rw Nat.ble eq at hb; omega | | | false = rfl | | rw hble, cond false at h | | exact h | | | | /-- extract the two value-slot equalities for a real non-sentinel slot. -/ | | theorem link at {a i e : Nat} ha : a < 225 hi : i < 2 ^ fla a | | hs : slotC cbof a i = e he : e < 2700 : | | slotV cbv0 a i = c4 e ∧ slotV cbv1 a i = c4 2700 + e := by | | have h := linkall spec a ha | | simp only linkA at h | | have hl := allBH sound 0 h i Nat.zero le by omega | | simp only hs at hl | | have hble : Nat.ble 2700 e = false := by | | cases hb : Nat.ble 2700 e with | | | true = rw Nat.ble eq at hb; omega | | | false = rfl | | rw hble, cond false, Bool.and eq true, Nat.beq eq, Nat.beq eq at hl | | have hadd : Nat.add 2700 e = 2700 + e := rfl | | rw hadd at hl | | exact hl | | | | theorem allI2 sound {p : Nat → Bool} : ∀ fuel a n : Nat , allI2 p fuel a n = true → | | ∀ i, a ≤ i → i < a + n → p i = true := by | | intro fuel | | induction fuel with | | | zero = | | intro a n h i h1 h2 | | have : Nat.beq n 0 = true := h | | rw Nat.beq eq at this | | omega | | | succ fuel ih = | | intro a n h i h1 h2 | | have hs : allI2 p fuel+1 a n = | | cond Nat.ble n 2 | | cond Nat.beq n 0 true | | cond Nat.beq n 1 p a p a .and p Nat.add a 1 | | allI2 p fuel a Nat.div n 2 .and | | allI2 p fuel Nat.add a Nat.div n 2 Nat.sub n Nat.div n 2 := rfl | | rw hs at h | | cases hb : Nat.ble n 2 with | | | true = | | rw hb, cond true at h | | have hn2 : n ≤ 2 := by rw ← Nat.ble eq ; exact hb | | cases hz : Nat.beq n 0 with | | | true = rw Nat.beq eq at hz; omega | | | false = | | rw hz, cond false at h | | have hz' : n ≠ 0 := by | | intro hcon; rw hcon at hz; simp at hz | | cases h1c : Nat.beq n 1 with | | | true = | | rw h1c, cond true at h | | rw Nat.beq eq at h1c | | have : i = a := by omega | | rwa this | | | false = | | rw h1c, cond false, Bool.and eq true at h | | have h1' : n ≠ 1 := by | | intro hcon; rw hcon at h1c; simp at h1c | | have hn : n = 2 := by omega | | rcases by omega : i = a ∨ i = a + 1 with rfl | hia | | · exact h.1 | | · have : Nat.add a 1 = a + 1 := rfl | | rw this at h | | rw hia | | exact h.2 | | | false = | | rw hb, cond false, Bool.and eq true at h | | obtain ⟨hL, hR⟩ := h | | rcases Nat.lt or ge i a + n/2 with hc | hc | | · exact ih a Nat.div n 2 hL i h1 by simp only div eqn ; omega | | · refine ih Nat.add a Nat.div n 2 Nat.sub n Nat.div n 2 hR i ? ? | | · simp only add eqn, div eqn ; omega | | · simp only add eqn, div eqn, sub eqn ; omega | | | | theorem leafX7 sound {W CBV i x : Nat} h : leafX7 8 W+1 CBV i = true | | hval : slotV CBV i = c4 x : | | ∀ w, t2 w + c4 x ≠ W := by | | intro w heq | | have ht := t2 ge one w | | simp only leafX7 at h | | rw hval at h | | cases hb : Nat.ble Nat.sub 8 W+1 Nat.mul 8 c4 x 1 with | | | true = | | rw Nat.ble eq at hb | | simp only sub eqn, mul eqn at hb | | omega | | | false = | | rw hb, cond false at h | | have hlt : ¬ Nat.sub 8 W+1 Nat.mul 8 c4 x ≤ 1 := by | | rw ← Nat.ble eq, hb ; simp | | simp only sub eqn, mul eqn at hlt | | have hv : Nat.sub 8 W+1 Nat.mul 8 c4 x = 2 w+3 2 w+3 := by | | simp only sub eqn, mul eqn | | have h8 := eight t2 w | | have : t2 w = W - c4 x := by omega | | omega | | rw hv at h | | exact sqTest2 sound h 2 w+3 rfl | | | | theorem xtreeOK7 sound {W : Nat} h : xtreeOK7 W = true : ∀ w x, t2 w + c4 x ≠ W := by | | intro w x heq | | have ht := t2 ge one w | | have hh : xtreeOK7 W = true := h | | simp only xtreeOK7, add eqn, mul eqn, sub eqn, pow eqn, mod eqn at hh | | rw Bool.and eq true, Bool.and eq true, Bool.and eq true, Bool.and eq true at hh | | obtain ⟨⟨⟨hchk0, hchk1⟩, h54⟩, htree0, htree1⟩ := hh | | rw Nat.blt eq at h54 | | set a := 8 W+1 % 225 with hadef | | set f := fla a with hfdef | | have hc4W : c4 x < W := by omega | | have hx54 : x < 5400 := by | | by contra hgt | | have : c4 5400 ≤ c4 x := c4 mono by omega | | omega | | set e := x % 2700 with hedef | | set k := x / 2700 with hkdef | | have helt : e < 2700 := by omega | | have hkb : k ≤ 1 := by omega | | have ha : a < 225 := Nat.mod lt by norm num | | cases hcf : colFree a e with | | | true = exact colfree case hcf hc4W w heq | | | false = | | have hbs := comp spec a ha e helt hcf | | obtain ⟨i, hi0, hilt, hslot⟩ := bsA sound hbs | | have hilt2 : i < 2 ^ f := by | | rw hfdef | | simpa only pow eqn using hilt | | have hslot' : slotC cbof a i = e := by | | rw slotC | | exact hslot | | have hlink := link at ha by rw hfdef at hilt2; exact hilt2 hslot' helt | | have hsort := sortA sound sortall spec a ha | | rw ← hfdef at hsort | | -- the value of c4 x through the blobs | | have hxval : if k = 0 then slotV cbv0 a i else slotV cbv1 a i = c4 x := by | | rcases by omega : k = 0 ∨ k = 1 with hk | hk | | · simp only hk, if pos rfl | | rw hlink.1 | | congr 1 | | omega | | · rw if neg by omega | | rw hlink.2 | | congr 1 | | omega | | rcases by omega : k = 0 ∨ k = 1 with hk | hk | | · -- k = 0 | | rw hk, if pos rfl at hxval | | set i0 := cutV cbv0 a W f+2 0 2^f with hi0def | | rcases Nat.lt or ge i i0 with hin | hout | | · have hleaf := allI2 sound htree0 i Nat.zero le by omega | | exact leafX7 sound hleaf hxval w heq | | · cases hq : Nat.beq i0 2^f with | | | true = rw Nat.beq eq at hq; omega | | | false = | | rw hq, cond false, Nat.blt eq at hchk0 | | -- W < slotV V0 i0 ≤ slotV V0 i = c4 x, contradiction | | have hs0 : slotC cbof a i0 ≤ slotC cbof a i := hsort i0 i hout hilt2 | | have hs0lt : slotC cbof a i0 < 2700 := by | | rw hslot' at hs0; omega | | have hl0 := link at ha by omega rfl hs0lt | | have hmono : slotV cbv0 a i0 ≤ slotV cbv0 a i := by | | rw hl0.1, hxval | | have : c4 slotC cbof a i0 ≤ c4 e := by | | apply c4 mono | | rw hslot' at hs0 | | exact hs0 | | have hxe : c4 x = c4 e := by congr 1; omega | | omega | | omega | | · -- k = 1 | | rw if neg by omega at hxval | | set i1 := cutV cbv1 a W f+2 0 2^f with hi1def | | rcases Nat.lt or ge i i1 with hin | hout | | · have hleaf := allI2 sound htree1 i Nat.zero le by omega | | exact leafX7 sound hleaf hxval w heq | | · cases hq : Nat.beq i1 2^f with | | | true = rw Nat.beq eq at hq; omega | | | false = | | rw hq, cond false, Nat.blt eq at hchk1 | | have hs0 : slotC cbof a i1 ≤ slotC cbof a i := hsort i1 i hout hilt2 | | have hs0lt : slotC cbof a i1 < 2700 := by | | rw hslot' at hs0; omega | | have hl1 := link at ha by omega rfl hs0lt | | have hmono : slotV cbv1 a i1 ≤ slotV cbv1 a i := by | | rw hl1.2, hxval | | have : c4 2700 + slotC cbof a i1 ≤ c4 2700 + e := by | | apply c4 mono | | rw hslot' at hs0 | | omega | | have hxe : c4 x = c4 2700 + e := by congr 1; omega | | omega | | omega | | | | theorem leafY7 sound {N r8 y : Nat} h : leafY7 N r8 y = true : | | ∀ w x, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x heq | | have ht := t2 ge one w | | cases hb : Nat.ble N Nat.add r8 c6 y with | | | true = | | rw Nat.ble eq, add eqn at hb | | omega | | | false = | | have hnb : ¬ N ≤ r8 + c6 y := by rw ← add eqn, ← Nat.ble eq, hb ; simp | | simp only leafY7, hb, cond false at h | | have : t2 w + c4 x = Nat.sub N Nat.add r8 c6 y := by | | simp only sub eqn, add eqn ; omega | | exact xtreeOK7 sound h w x this | | | | theorem ytree7 parts {N fy r8 : Nat} h1 : allB leafY7 N r8 fy 0 = true | | h2 : Nat.ble N Nat.add r8 c6 Nat.pow 2 fy = true : | | ∀ w x y, t2 w + c4 x + c6 y + r8 ≠ N := by | | intro w x y heq | | rw Nat.ble eq, add eqn at h2 | | have ht := t2 ge one w | | rcases Nat.lt or ge y 2 ^ fy with hy | hy | | · exact leafY7 sound allB sound 0 h1 y Nat.zero le by omega w x heq | | · have hc : c6 Nat.pow 2 fy ≤ c6 y := by | | apply c6 mono; rw pow eqn ; exact hy | | omega | | | | theorem leafZ7 sound {N fy z : Nat} h : leafZ7 N fy z = true : | | ∀ w x y, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y heq | | have ht := t2 ge one w | | cases hb : Nat.ble N c8 z with | | | true = rw Nat.ble eq at hb; omega | | | false = | | simp only leafZ7, hb, cond false, Bool.and eq true at h | | exact ytree7 parts h.1 h.2 w x y heq | | | | theorem master7 {N fy fz : Nat} | | h : allB leafZ7 N fy fz 0 = true | | htop : Nat.ble N c8 Nat.pow 2 fz = true : | | ∀ w x y z, t2 w + c4 x + c6 y + c8 z ≠ N := by | | intro w x y z heq | | have ht := t2 ge one w | | rcases Nat.lt or ge z 2 ^ fz with hz | hz | | · exact leafZ7 sound allB sound 0 h z Nat.zero le by omega w x y heq | | · rw Nat.ble eq at htop | | have hc : c8 Nat.pow 2 fz ≤ c8 z := by | | apply c8 mono; rw pow eqn ; exact hz | | omega | | | | end D | | EOF | | tail -3 /tmp/b7.log; ls -la devlib/ | grep -i blobs7 | | | | | | 233 --- TOOL bash --- | | <stdout </stdout | | <stderr </stderr | | <returncode 1</returncode | | | | 234 --- ASSISTANT --- | | bash | | | | cat /tmp/b7.log; ps -C lean -o pid,rss,etime | tail -2; ls /workspace/leanproject/devlib/ | | | | | | 234 --- TOOL bash --- | | 7114 0 02:26:03 | | 11933 6395272 06:46 | | Blobs.olean | | Checker.olean | | Checker5.olean | | Checker6.olean | | V5Defs.olean | | V6Defs.olean | | | | | | 235 --- ASSISTANT --- | | Blobs7 is still compiling after 6:46 with 6.4GB RSS, and I'm suspecting the issue might be in how Lean parses those massive hex literals. Converting a 2-million-digit hex number to a Nat through the OfNat mechanism could be quadratic in the elaborator — each digit requires a multiply-add operation, so 2M digits might mean 4 trillion bit operations, which could easily take hours. | | | | Let me sanity-check this against the earlier Blobs.lean compile: 618K decimal digits took about 2m24s, and if that's quadratic, then scaling to 2.37M hex digits should be roughly 68 minutes just for literal parsing. The real problem is this cost happens again at verification time when the final file is checked. | | | | I'm considering splitting the blob into 64 smaller chunks of around 37K hex digits each, then assembling them with bitwise operations — that would reduce the parsing cost from quadratic in 2.37M down to 64 separate quadratic parses of 37K, which is thousands of times faster. The chunks would stay as unevaluated expressions in the definition, and the kernel would cache the result, though each theorem referencing the assembled blob might still need to recompute the OR-chain. | | | | Actually, I should verify whether Lean's literal parsing is truly quadratic here — the 2m24s for Blobs.lean included Mathlib import overhead and olean writing, so I need to measure a bare file with just a large hex literal to isolate the real cost. The current Blobs7 compile is running now, and I can compare smaller test cases 200K vs 400K hex digits to estimate the scaling exponent. | | Blobs7 is slow to compile — likely quadratic literal parsing. Let me measure the scaling while it runs: | | bash | | | | cd /tmp && python3 -c " | | import random | | random.seed 5 | | for n in 100000,200000,400000 : | | v=random.getrandbits n 4 | | open f'/tmp/lit{n}.lean','w' .write 'def X : Nat := 0x%x\n' % v | | " && for n in 100000 200000 400000; do /usr/bin/env time -f "$n hexdigits: %e s" lean lit$n.lean 2 &1 | tail -1; done | | | | | | 235 --- TOOL bash --- | | /usr/bin/env: 'time': No such file or directory | | /usr/bin/env: 'time': No such file or directory | | /usr/bin/env: 'time': No such file or directory | | | | | | 236 --- ASSISTANT --- | | bash | | | | cd /tmp && for n in 100000 200000 400000; do S=$ date +%s.%N ; lean lit$n.lean; E=$ date +%s.%N ; echo "$n hexdigits: $ echo "$E-$S"|bc s"; done | | | | | | 236 --- TOOL bash --- | | ERROR Command timed out before completing. | | | | 237 --- ASSISTANT --- | | bash | | | | cd /tmp && S=$ date +%s.%N ; timeout 250 lean lit100000.lean && { E=$ date +%s.%N ; echo "100000 hexdigits: $ echo "$E-$S"|bc s"; } | | | | | | 237 --- TOOL bash --- | | 100000 hexdigits: 16.983370287 s | | | | | | 238 --- ASSISTANT --- | | I'm seeing a quadratic performance issue with the literal parsing—100K hex digits takes 17 seconds, which scales to roughly 2.65 hours for 2.37M digits. This matches the observed behavior in Blobs.lean where 618K decimal digits previously took about 2 minutes 24 seconds, confirming the pattern is consistent across different numeric formats. | | | | The solution is to split the blob into smaller chunks and assemble them using bitwise operations—concatenating chunks with left-shift and OR operations in a balanced tree structure that the kernel evaluates once per theorem and caches. The tradeoff is finding the optimal chunk size: smaller chunks reduce per-chunk parsing time quadratic in chunk size but increase the number of definitions and per-definition overhead. Testing different sizes suggests around 16K hex digits per chunk 64 kilobits gives a reasonable balance, though the exact sweet spot depends on whether the per-definition overhead or parsing time dominates. | | | | But wait—maybe the real bottleneck isn't the chunking strategy itself but the underlying parser. The quadratic slowdown might be coming from Lean's C++ lexer converting the hex string to a Nat value, which apparently uses a naive digit-by-digit loop instead of something subquadratic like GMP's divide-and-conquer approach. That would explain why 100K hex digits takes 17 seconds when GMP could handle it in milliseconds. | | | | I'm exploring alternatives: could I use Nat.binLit or Nat.fromExpr instead? Or maybe store the blob as a String and convert it via a kernel-computable function like hexToNat that operates over the String's character list, since the kernel has special support for String literals? | | | | But iterating through 2.37M characters in the kernel via List operations would be too slow. A better approach is to build the Nat from smaller chunks using balanced arithmetic — parsing each chunk costs O s² where s is the chunk size, so total cost scales linearly with the blob size for a fixed chunk size. With 4K hex digits per chunk, each parse takes around 27ms plus overhead, and splitting the 2.37M character blob across ~593 chunks means roughly 1200+ definitions, but that doesn't actually inflate the file since the total bytes stay the same. | | | | Actually, instead of defining separate chunks, I could write a single definition with a literal list of chunk values, where each element parses cheaply and an assemble function folds them together with shifts — this gets evaluated once per theorem via the kernel cache. But the assembly cost is significant: 600 shift/or operations on 8Mbit values means each operation near the end is roughly a 1MB memcopy, totaling around 300MB of data movement or 0.1-0.3 seconds per theorem evaluation, which multiplied across 5000 chunks becomes 8-25 minutes. A balanced tree assembly would reduce the total data movement to N log K instead, where each level moves less data overall. | | | | With a tree approach, the 8Mbit chunks across 10 levels means only about 10MB total movement per evaluation — roughly 5 milliseconds — which is much better. I could implement this either as a divide-and-conquer function over arrays in the kernel which has some overhead but handles 600 elements fine in about 20 milliseconds , or more simply, have the generator emit a balanced binary expression tree with 600 leaves using nested parentheses and bitwise operations, keeping the expression depth logarithmic. | | | | For the actual chunk size, I'm weighing the tradeoffs: 4K hex digits parse in about 27 milliseconds each, so 593 chunks would take roughly 16 seconds total plus overhead. Going larger to 16K hex would be slower overall. A 2K hex approach with 1186 chunks would parse faster at around 7 milliseconds each, totaling about 8 seconds, though the expression tree gets deeper. | | | | I'm settling on 2048 hex digits per chunk, which gives me around 961 chunks for the C4B0 data. The key insight is building a balanced binary tree where each chunk is shifted by its position times the bit width, so I'm recursively constructing nodes that either emit a literal for single chunks or combine subtrees with appropriate bit shifts. | | | | For the Lean implementation, I'll use Nat.lor and Nat.shiftLeft directly rather than the symbolic operators to keep things clean, since the kernel reduces these instances fine anyway. Hex literals in Lean work with both uppercase and lowercase, so that's straightforward. Now I'm applying this approach to the SELB data, which is currently 618K decimal digits and should compress down significantly. Rebuilding the Blobs.lean file invalidates the downstream .olean chain, so I need to recompile Blobs, V5Defs, Checker5, V6Defs, Checker6, Blobs7, V7Defs, and Checker7 — roughly 15 minutes total with contention, which is acceptable. The critical constraint is keeping the SELB value identical as a literal after evaluation so existing proofs remain unaffected, then using the same chunked-expression form in the final file. | | | | For the parse cost, I'm weighing chunk size tradeoffs: with 4096 hex characters per chunk, I get around 1316 total literals across roughly 1300 chunks with minimal overhead and shallow nesting depth. This keeps parse time negligible even for the 2.37M hex characters involved. So I'll proceed with rewriting both Blobs.lean and Blobs7.lean using the chunked hex approach. | | | | Now I need to update the gen spec.py framework to inline these chunked definitions by reading the Dev files and extracting the SELB blocks—my parser already handles multi-line definitions correctly, so whether the expression spans one long line or wraps across multiple lines, it should work fine. | | I found that literal parsing is quadratic in complexity, taking around 17 seconds per 100K hex digits, which would take hours for our blobs. I'll rebuild the blob files using chunked literals assembled with a balanced expression tree instead. | | bash | | | | pkill -x lean; cd /workspace/leanproject && python3 - <<'EOF' | | import pickle | | FLB,OFFB,SELB,OFFB46,C4B0,C4B1=pickle.load open "/tmp/blobs7.pkl","rb" | | HEX=4096 hex chars per chunk | | B=HEX 4 bits per chunk | | def chunks v : | | out= | | while v 0: | | out.append v & 1<<B -1 | | v = B | | if not out: out= 0 | | return out | | def tree ch, lo, hi : | | if hi-lo==1: return "0x%x" % ch lo | | mid= lo+hi //2 | | left=tree ch,lo,mid ; right=tree ch,mid,hi | | return " Nat.lor %s Nat.shiftLeft %s %d " % left, right, B mid-lo | | def emit name, v : | | ch=chunks v | | return "def %s : Nat := %s\n" % name, tree ch,0,len ch | | with open "Dev/Blobs.lean","w" as f: | | f.write "import Checker\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def FLB : Nat := %d\n" % FLB | | f.write "def OFFB : Nat := %d\n" % OFFB | | f.write emit "SELB", SELB | | f.write "end D\n" | | with open "Dev/Blobs7.lean","w" as f: | | f.write "import Checker\nimport Blobs\nset option linter.style.moduleDocstring false\nnamespace D\n" | | f.write "def OFFB46 : Nat := %d\n" % OFFB46 | | f.write emit "C4B0", C4B0 | | f.write emit "C4B1", C4B1 | | f.write "end D\n" | | sanity: python-eval the tree text | | import re | | def check name, path, val : | | txt=open path .read | | m=re.search r"def %s : Nat := . \n" % name, txt | | expr=m.group 1 .replace "Nat.lor","lor " .replace "Nat.shiftLeft","shl " | | def lor a,b : return a|b | | def shl a,s : return a<<s | | convert to python syntax: lor X shl Y n - lor X, shl Y, n | | simpler: recursive parse | | import ast | | s=m.group 1 | | s=re.sub r"\ Nat.lor ", " ", s | | do a manual eval with a tiny parser: | | pos= 0 | | def parse s : | | def skip : | | while pos 0 <len s and s pos 0 ==' ': pos 0 +=1 | | skip | | if s pos 0 ==' ': | | pos 0 +=1 | | skip | | assert s.startswith "Nat.lor",pos 0 or True | | if s.startswith "Nat.lor",pos 0 : | | pos 0 +=7 | | a=parse s ; b=parse s | | skip ; assert s pos 0 ==' '; pos 0 +=1 | | return a|b | | elif s.startswith "Nat.shiftLeft",pos 0 : | | pos 0 +=13 | | a=parse s ; b=parse s | | skip ; assert s pos 0 ==' '; pos 0 +=1 | | return a<<b | | else: raise Exception "bad "+s pos 0 :pos 0 +20 | | else: | | m2=re.match r" 0x 0-9a-f +|\d+ ", s pos 0 : | | pos 0 +=len m2.group 1 | | return int m2.group 1 ,0 | | v=parse m.group 1 | | print name, "ok" if v==val else "MISMATCH" | | check "SELB","Dev/Blobs.lean",SELB | | check "C4B0","Dev/Blobs7.lean",C4B0 | | check "C4B1","Dev/Blobs7.lean",C4B1 | | EOF | | | | | | 238 --- TOOL bash --- | | SELB ok | | C4B0 ok | | C4B1 ok | | | | | | 239 --- ASSISTANT --- | | bash | | | | cd /workspace/leanproject && nohup bash -c ' | | set -e | | export LEAN PATH EXTRA=devlib | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Blobs.lean -o devlib/Blobs.olean" | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/V5Defs.lean -o devlib/V5Defs.olean" | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker5.lean -o devlib/Checker5.olean" | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/V6Defs.lean -o devlib/V6Defs.olean" | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker6.lean -o devlib/Checker6.olean" | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Blobs7.lean -o devlib/Blobs7.olean" | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/V7Defs.lean -o devlib/V7Defs.olean" | | time lake env sh -c "LEAN PATH=\$LEAN PATH:devlib lean Dev/Checker7.lean -o devlib/Checker7.olean" | | echo ALLDONE' /tmp/chain.log 2 &1 & echo bg; sleep 240; grep -E "error|ALLDONE|real" /tmp/chain.log | head; ls devlib/ | | | | | | 239 --- TOOL bash --- | | bg | | real 0m28.338s | | Blobs.olean | | Checker.olean | | Checker5.olean | | Checker6.olean | | V5Defs.olean | | V6Defs.olean | | | | | | 240 --- ASSISTANT --- | | Blobs.lean is now compiling much faster at 28 seconds, and while V5Defs recompiles which could take several minutes , I'm updating the v7 generator to pull the framework from Checker.lean, incorporate the units from Blobs.lean and V5Defs, and selectively include specific units from Checker5 while excluding the leaf and tree-related ones. | | | | For V6Defs and Checker6, I'm including the sorting and specification units but skipping the tree validation pieces, then pulling all of V7Defs and Checker7. The chunk emission will use leafY7/leafZ7 with a count estimator from sim7.count pair, and I need to verify that colfree case doesn't depend on anything v6-specific—checking against the whitelist shows it only uses v mod eq, colFree, and a few other whitelisted functions. | | | | I'm updating gen spec.py to add per-file whitelists and replace blob emission by reading directly from the Blobs.lean and Blobs7.lean units, then using sim7.count pair for the exact v7 estimator with a cost model based on leaf pair counts plus per-pair overhead. | | | | Estimating leaf-equivalents per pair... | | While the chain rebuilds, update the generator to v7: | | bash | | | | cd /workspace/gen && python3 - <<'PYEOF' | | c=open 'gen spec.py' .read | | 1. framework text: new multi-file whitelists | | old fw=c c.index "CHECKER KEEP =" :c.index " ---------- arithmetic ----------" | | new fw='''CHECKER KEEP = """allB allB zero allB succ allB sound t2 p4 c4 p6 c6 p8 c8 t2 def p4 def c4 def p6 def | | c6 def p8 def c8 def t2 ge one eight t2 c4 mono c6 mono c8 mono maskBit sqAll sqAll sound | | newtonAux newton bracketOK bracketOK sound mul eqn add eqn sub eqn div eqn mod eqn pow eqn | | choose2 eq choose4 eq choose6 eq choose8 eq A eq zero c4 alt | | R1 R2 R3 R4 K1 K2 K3 K4 sqAllK1 sqAllK2 sqAllK3 sqAllK4 maskK1 all maskK2 all maskK3 all | | maskK4 all sqTest2 beq land zero sqTest2 sound allB4 allB4 sound allBH allBH sound""".split | | | | CHECKER5 KEEP = """c4 mul24 c4 step c4 period aux c4 period v mod eq comp spec""".split | | V6 KEEP = """slotC sortA sortG SORTALL sortT 0 sortT 1 sortT 2 sortT 3 sortL 0 sortL 1 sortall true""".split | | CHECKER6 KEEP = """sortall spec sortA sound colfree case""".split | | | | def framework text : | | out= | | units, order = parse units f"{ROOT}/Dev/Checker.lean" | | for n in order: | | if n in CHECKER KEEP: out.append units n | | for fn, keep in "Blobs",None , "V5Defs",None , "Checker5",CHECKER5 KEEP , | | "V6Defs",V6 KEEP , "Checker6",CHECKER6 KEEP , | | "Blobs7",None , "V7Defs",None , "Checker7",None : | | units, order = parse units f"{ROOT}/Dev/{fn}.lean" | | for n in order: | | if keep is None or n in keep: | | out.append units n | | return "\\n\\n".join out | | | | ''' | | c=c.replace old fw,new fw | | 2. Gen: use v7 names and sim7-based counts | | c=c.replace 'leafY5','leafY7' .replace 'leafZ5','leafZ7' .replace 'ytreeOK5',' unused ' | | open 'gen spec.py','w' .write c | | print "stage1 done" | | PYEOF | | grep -n "ytreeOK\|leafY7\|leafZ7" gen spec.py | head | | | | | | 240 --- TOOL bash --- | | stage1 done | | 125: self.emit f"theorem {nm} : allB leafY7 {self.N} c8 {z} {f} {a} = true := by decide +kernel" | | 129: self.emit f"""theorem {nm} : allB leafY7 {self.N} c8 {z} {f} {a} = true := by | | 140: self.emit f"theorem {nm} : allB leafZ7 {self.N} {self.fy} {f} {a} = true := by decide +kernel" | | 147: self.emit f"""theorem {nm} : allB leafZ7 {self.N} {self.fy} 0 {z} = true := by | | 149: simp only leafZ7 | | 157: self.emit f"""theorem {nm} : allB leafZ7 {self.N} {self.fy} {f} {a} = true := by | | | | | | 241 --- ASSISTANT --- | | Working through the remaining generator issues with the Lz proof — I need to handle the conditional logic where after rewriting with the false case, the goal reduces to proving the conjunction is true, which resolves through the tree root and base case with reflexivity. There's a simp only ytreeOK5 line in the current generated proof that needs to be removed. | | | | For the per-pair leaf count, I'm updating the formula from v5's 2^f / 2^ f+1 to v7 using the cutV-based approach through sim7.count pair, and I need to add the sim7 import to the initialization. The validate pair function in v7 doesn't require xcap or newton checks — instead I'm verifying that W stays below the threshold and confirming the boundary conditions hold by construction since the cut operation is deterministic and matches the Python mirror. I'm keeping the assertion for W < C5400 and verifying the Bz constraint that N ≤ c8 z + c6 512 is satisfied through the c6 2^fy ≥ N assertion in the run function. Finally, I need to adjust the estimate print output to reflect the corrected cost per leaf calculation. | | bash | | | | cd /workspace/gen && python3 - <<'PYEOF' | | c=open 'gen spec.py' .read | | fix imports for sim7-based counts | | c=c.replace '''import sys, re, pickle, argparse | | sys.set int max str digits 2000000 ''','''import sys, re, pickle, argparse | | sys.set int max str digits 8000000 | | sys.path.insert 0,"/tmp" ''' | | replace Gen. init pair counting with v7 counts | | old=''' def init self,N,fy=9,fz=8,cap=40000 : | | self.N=N; self.fy=fy; self.fz=fz; self.cap=cap | | FLB,OFFB,SELB=pickle.load open "/tmp/blobs.pkl","rb" | | self.META= | | for a in range 225 : | | f= FLB 4 a &15 | | self.META.append f | | self.out= | | self.nchunk=0; self.ncomb=0; self.totleaves=0; self.maxchunk=0 | | per z,y leaf counts | | self.zy={} | | self.zleaves= 0 2 fz | | for z in range 2 fz : | | r8=c8 z ; tot=0 | | for y in range 2 fy : | | if N<=r8: | | c=1 | | elif N<=r8+c6 y : | | c=1 | | else: | | W=N-r8-c6 y | | self.validate pair W | | a= 8 W+1 %225; f=self.META a | | c=2 f+1 if W =C2700 else 2 f | | c+=6 | | self.zy z,y =c; tot+=c | | self.zleaves z =tot | | def validate pair self,W : | | checks that the runtime per-pair guards will hold | | assert W < C5400, self.N,W | | xcap=newton isqrt newton isqrt 24 W | | assert W < c4 xcap+1 , "xcap fail",W | | if W =C2700: | | assert W < c4 5400 | | else: | | assert W < c4 2700 ''' | | new=''' def init self,N,fy=9,fz=8,cap=40000 : | | import sim7 | | self.N=N; self.fy=fy; self.fz=fz; self.cap=cap | | self.out= | | self.nchunk=0; self.ncomb=0; self.totleaves=0; self.maxchunk=0 | | per z,y leaf counts exact v7 counts + per-pair overhead | | self.zy={} | | self.zleaves= 0 2 fz | | for z in range 2 fz : | | r8=c8 z ; tot=0 | | for y in range 2 fy : | | if N<=r8: | | c=1 | | elif N<=r8+c6 y : | | c=1 | | else: | | W=N-r8-c6 y | | assert W < C5400, N,z,y,W | | c=sim7.count pair W +8 | | self.zy z,y =c; tot+=c | | self.zleaves z =tot''' | | assert old in c | | c=c.replace old,new | | fix Lz emission leafZ7 inline ytree structure | | old=''' self.emit f"""theorem {nm} : allB leafZ7 {self.N} {self.fy} 0 {z} = true := by | | rw allB zero | | simp only leafZ7 | | rw ez{z}, cond false | | simp only unused | | rw {yroot}, bz{z} | | rfl""" ''' | | new=''' self.emit f"""theorem {nm} : allB leafZ7 {self.N} {self.fy} 0 {z} = true := by | | rw allB zero | | simp only leafZ7 | | rw ez{z}, cond false | | rw {yroot}, bz{z} | | rfl""" ''' | | assert old in c | | c=c.replace old,new | | fix master5 - master7 and est print | | c=c.replace "master5 {zroot} htop5","master7 {zroot} htop5" | | c=c.replace "est kernel time {g.totleaves 160e-6/60:.1f} min","est kernel time {g.totleaves 130e-6/60:.1f} min" | | open 'gen spec.py','w' .write c | | print "stage2 done" | | PYEOF | | tail -5 /tmp/chain.log | | | | | | 241 --- TOOL bash --- | | stage2 done | | | | real 0m28.338s | | user 0m7.503s | | sys 0m1.912s | | | | | | 242 --- ASSISTANT --- | | bash | | | | sleep 240; grep -E "error|ALLDONE|real" /tmp/chain.log; ls /workspace/leanproject/devlib/; tail -1 /tmp/scan99c.err | | | | | | 242 --- TOOL bash --- | | real 0m28.338s | | Blobs.olean | | Checker.olean | | Checker5.olean | | Checker6.olean | | V5Defs.olean | | V6Defs.olean | | block 7/34 done marks=168086213512 zeros=0 | | | | | | 243 --- ASSISTANT --- | | The V5Defs computation is taking time on its 16 COMP chunk, so I'm waiting for it to complete while continuing to scan through block 7 of 34, checking values up to around 8.9 trillion with no zeros found yet. Once the scan finishes all 34 blocks at 2 trillion, I'll need to decide whether to extend the search further or reassess the approach. | | | | At 2 trillion, the estimated count is around 90 million, which would require about 3.3 hours of kernel time—potentially expensive, so I might need to reconsider or continue scanning into the 3 trillion range. I should also plan to scan other thin classes in parallel once this machine's current scan completes. Once Checker7 is ready, I'll recalibrate the benchmark to measure time and memory per leaf with the new v7 implementation, since the lighter leaf structure might reduce expression churn. Then I'll run a full system test with the target dataset to verify the expected error location. | | bash | | | | sleep 270; grep -E "error|ALLDONE|real" /tmp/chain.log; ps -C lean -o pid,rss,etime | tail -1 | | | | | | 243 --- TOOL bash --- | | real 0m28.338s | | real 11m11.278s | | real 0m36.680s | | real 1m12.817s | | 12486 1100452 00:02 | | | | | | 244 --- ASSISTANT --- | | bash | | | | sleep 270; grep -E "error|ALLDONE|real" /tmp/chain.log; ls /workspace/leanproject/devlib/ | paste -sd' ' | | | | | | 244 --- TOOL bash --- | | real 0m28.338s | | real 11m11.278s | | real 0m36.680s | | real 1m12.817s | | real 0m35.137s | | real 1m15.511s | | real 1m59.745s | | Dev/Checker7.lean:154:8: error: omega could not prove the goal: | | Dev/Checker7.lean:174:37: error: omega could not prove the goal: | | Dev/Checker7.lean:197:37: error: omega could not prove the goal: | | real 0m26.880s | | Blobs.olean Blobs7.olean Checker.olean Checker5.olean Checker6.olean V5Defs.olean V6Defs.olean V7Defs.olean | | | | | | 245 --- ASSISTANT --- | | bash | | | | grep -A 30 "Checker7.lean:154" /tmp/chain.log | head -40 | | | | | | 245 --- TOOL bash --- | | Dev/Checker7.lean:154:8: error: omega could not prove the goal: | | a possible counterexample may satisfy the constraints | | r ≥ 0 | | q ≥ 0 | | p ≥ 0 | | 0 ≤ o ≤ 2699 | | m ≥ 0 | | l ≥ 0 | | l - m ≤ -1 | | l - n ≤ -1 |