Fermat’s margin was too narrow. Lean’s runs to 13 million lines.
Development
Agents write 13 million lines of Lean for the first checked Fermat proof
Claim
Claude agents spent 11 days writing 13 million lines of Lean for the first computer-checked proof of Fermat's Last Theorem, which Kevin Buzzard called an extraordinary autoformalization achievement.
Reported metric: 13M lines in 11 days
Reporting date: (not necessarily the event date)
Sources
Attribution and reporting linked by this record; links do not imply independent verification.
- Welcome to September 6, 2026 (theinnermostloop.substack.com)
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