Nah, he did not. He proved that "it" cannot prove its own consistency. (Where it can express Peano arithmetic.) But "it" is not the whole of mathematics. Ther

Nah, he did not. He proved that "it" cannot prove its own consistency. (Where it can express Peano arithmetic.) But "it" is not the whole of mathematics. There are "weak" systems that can prove their own consistency. ( https://en.wikipedia.org/wiki/Self-verifying_theories https://en.wikipedia.org/wiki/Self-verifying_theories )