Anthropic uses Claude to formalize proof of Fermat’s Last Theorem

Anthropic PBC utilized Claude agents to create the first computer-verifiable proof of Fermat’s Last Theorem. The project involved a team of autonomous agents working over 11 days, producing thirteen million lines of Lean and nearly 30,000 intermediate theorems. While initial attempts failed due to poor collaboration and state tracking, the team eventually succeeded by implementing a shared to-do list. This achievement resulted in approximately six billion output tokens to formalize the highly complicated mathematical hypothesis.