Formal Verification is catching up with cutting-edge Mathematics

Formalization has trailed cutting-edge mathematics for some time: the four color theorem was proved in 1976, but it wasn't formally verifed until 2005. This was one of the objections of the QED manifesto in 1993: Objection 4. Mechanically checked formality is impossible. There is no evidence that extremely hard proofs can be put into formal form in less than some utterly ridiculous amount of work.…