Anthropic's Claude Fable 5 and OpenAI's GPT-5.5 Pro each generated verified solutions to an unsolved number theory problem involving the absolute Galois group of the 2-adic numbers, marking the second…
A third of official solutions in Epoch's FrontierMath benchmark contained errors, making reward-hacking the only way to pass, according to a post by LessWrong user 1a3orn. The author argues that flawe…
Anthropic's Claude Fable 5 scored 161 on the Epoch Capabilities Index, surpassing OpenAI's GPT-5.5 Pro at 159, with dominant performances in math and software engineering benchmarks. The model achieve…
Anthropic's Claude Fable 5 achieved 88 percent accuracy on the hardest FrontierMath tier, surpassing OpenAI's GPT-5.5 by 13 points. The result marks a dramatic improvement from Anthropic's previous Op…
Epoch AI disclosed on May 11, 2026, that an internal audit of its FrontierMath benchmark, a 350-problem test developed with over 60 mathematicians to evaluate AI reasoning, found fatal errors in rough…
Cognition introduced FrontierCode, a new benchmark that evaluates code on mergeability rather than just unit-test passing, with tasks built by open-source maintainers requiring over 40 hours each. The…