Classification of Finite Simple Groups Formalized in Lean

A project has produced a formalization of the classification of finite simple groups in the Lean proof assistant, as described on a dedicated project website. The source is a Hacker News post that links to that site and has drawn modest attention, with 11 points and 6 comments at the time of posting. The original item provides few further details, so the scope, authors, and verification status of the formalization cannot be confirmed from it. The classification is a landmark result in group theory, long regarded as one of the largest collaborative proofs in mathematics.