Claude proved 239 entry points across 123 open-source libraries never crash
Anthropic's Frontier Red Team and Theorem used Claude to write machine-checked proofs that 239 entry points across 123 OSS-Fuzz libraries never crash on any input up to 64 MB. Formal verification means a proof checker confirms, step by step, that compiled code meets a written rule. The proofs total about 180 million lines of Rocq and hold only for single-threaded static binaries on a RISC-V CPU running Linux. Claude also found bugs that trillions of test runs had missed.