Formalizing Fermat's Last Theorem

Claude produced the first end-to-end, computer-checked proof of Fermat’s Last Theorem in 11 days, writing 13 million lines of Lean code and proving 29 500 intermediate theorems. The work follows a 2024 community effort led by Kevin Buzzard to formalize Andrew Wiles’s 1995 129-page proof, and demonstrates that AI can autonomously formalize complex mathematical arguments.