Anthropic announced September 5 that dozens of Claude agents formalized Fermat's Last Theorem in machine-checkable Lean code in 11 days, producing over 13 million lines proving more than 29,000 supporting theorems.
A companion document described agents cross-checking each other's work, with completion confirmed when the root theorem returned zero open leaves. A dev.to article disputed the claim the same day, arguing that Claude's result covers only FLT for regular primes, a special case, not the general theorem.