Anthropic says Claude produced the first complete computer-checked proof of Fermat’s Last Theorem over 11 largely autonomous days using Lean, a system for checking mathematical proofs. In the Anthropic repository, PROOF-PATH.md names every step and the Lean theorem that carries it.
The author of Xena Project says they compiled the codebase and checked it, and it checks out.
Claim check:
- Anthropic says Claude produced the first complete computer-checked proof of Fermat’s Last Theorem over 11 largely autonomous days using Lean. (confirmed by the publication itself: evidence; «In 11 days, working largely autonomously, Claude produced the first end-to-end, computer-checked proof of FLT.»)
- In the Anthropic repository, PROOF-PATH.md names every step and the Lean theorem that carries it. (confirmed by the publication itself: evidence; «PROOF-PATH.md names each step and the Lean theorem that carries it»)
- The author of Xena Project says they compiled the codebase, ran comparator, and it checks out. (confirmed by the publication itself: evidence; «I’ve compiled the code base and run comparator on it — it checks out.»)
Publications:
- https://xenaproject.wordpress.com/2026/09/04/flt-anthropic-has-beaten-me-to-it
- https://mbmccoy.dev/posts/mathematical-conservatory
Primary sources:
- https://anthropic.com/research/formalizing-fermats-last-theorem
- https://github.com/anthropics/fermats-last-theorem
- https://www.anthropic.com/research/formalizing-fermats-last-theorem
- https://arxiv.org/pdf/2608.27305
- https://arxiv.org/pdf/2303.10130
- https://leidendeclaration.ai/
- https://www.tha.de/~glasauer/publ/diss.pdf
score 51.3 · kind research · revision 4 · stories st-51x1qn