1,000 Claude Fable 5.2 agents formalized Fermat's Last Theorem in 30 hours
Anthropic's first formalization took 11 days with a custom harness and a human guiding it
Fable 5.2 used no math references, a third of the tokens, and wrote a proof 7x shorter
Opus 5.5 with the same 1,000 agents: 27% done after 30 hours