TL;DR: Anthropic's Claude completed the first machine-verified formalization of Fermat's Last Theorem in Lean, a feat experts expected to take years.
Summary: Anthropic's Claude produced a complete formal proof of Fermat's Last Theorem using the Lean proof assistant. The proof totals over 13 million lines of code, making it the largest Lean proof ever written. It also verifies more than 29,000 supporting theorems, many from mathematical areas never before formalized.
Why it matters: AI-assisted proof formalization could drastically reduce the burden of verifying new mathematics and make machine-checkable proofs practical at elite levels. AI builders should watch Lean-based formal verification workflows and explore the released proof and process details for patterns in long-horizon reasoning.
Source: x_com