Claude agents wrote 13 million lines of Lean in 11 days to prove Fermat's Last Theorem. The mathematician funded to do it says it is not new maths.

Anthropic's Claude AI completed the first machine-checked formalization of Fermat's Last Theorem in Lean 4, verifying over 29,500 theorems

Anthropic's Claude formalized Fermat's Last Theorem in 11 days. Anthropic has the best AI model by September 2026 at 85.5% YES.