Anthropic formalizes Fermat's Last Theorem in Lean 4

Fermat's Last Theorem in Lean 4

Anthropic open-sourced a Lean 4 project that formalizes the proof of Fermat's Last Theorem into machine-checkable code. The theorem states xⁿ + yⁿ = zⁿ has no positive integer solutions for n>2, proven by Wiles in 1994. Lean 4 is a proof assistant that turns human reasoning into formally verified steps. This project ports an existing proof into Lean 4, not a new theorem. The post doesn't disclose how many person-hours were spent or whether Wiles was involved.