A computer-checked proof of Fermat's Last Theorem has been completed using the Lean programming language, with a significant portion of the work done autonomously by a system called Claude over 11 days. The proof is a major step towards automatic formalization of mathematical literature and can help reduce the burden of verifying mathematical proofs. The achievement demonstrates the potential of AI in formalizing large swaths of mathematics. The formalization process was expected to take years, but Claude's ability to work autonomously and collaborate with other agents enabled it to complete the proof quickly.