Anthropic reports a complete Lean formalization of Fermat’s Last Theorem
The September 4 announcement puts AI-assisted verification of established mathematics in focus.
A landmark in checking mathematics
Anthropic says Claude formalized Fermat’s Last Theorem in Lean over 11 days, coordinating agents through Prove2Me. The September 4 announcement concerns verification of an established theorem, rather than a newly discovered mathematical result.
What readers can inspect
The released repository includes proof code, a walkthrough and verification scripts. Its authors report checks with Lean and a second kernel, plus a comparator that matches the conclusion to Mathlib’s theorem statement. These are reported checks; MathsAI has not independently rebuilt the proof.
The repository labels the release an unmaintained research artifact. Readers should consult formal statements, since intermediate theorem names do not guarantee their intended meaning. Turning such artifacts into accessible mathematical explanations remains valuable work.