LEAN

Anthropic says Claude worked largely autonomously for 11 days to formalize Fermat's Last Theorem in Lean. The developer lesson is less about one theorem and more about verified repo-scale research artifacts.

OpenAI's next model, codenamed Astra, produced results on ten problems open for at least a decade - including non-sofic groups and Erdős problems 146, 180, and 183 - with every argument formalized as a Lean certificate.