FLT: Anthropic has beaten me to it

I guess technically it was revealed to the world by a coffee shop in Islington on Insta, but an hour later it was officially announced by Anthropic: one of their internal models, using the prove2.me platform, has formalized a complete proof of Fermat’s Last Theorem (FLT) in Lean. This is the final theorem to be formalized in Freek Wiedijk’s famous list of 100 formalization challenges and thus wraps up this 20-year-old benchmark. Congratulations to Anthropic! Mathematical details The proof is not the modern proof which I have been formalizing myself following ideas of Khare, Taylor etc, but the Darmon–Diamond–Taylor exposition from 1995 of the Wiles–Taylor–Wiles argument, via the Langlands–Tunnell theorem and Ribet’s level-lowering theorem. Anthropic’s repository develops Fontaine theory (to study flat deformations of Galois representations) and develops enough of Mazur’s work on the Eisenstein ideal to conclude that no Frey curve can have a point of order . This means that their FLT…