Category: History of science

TL;DR: I found an error in most logic textbooks (in metalogic, not in ZF). That’s a security hazard. This shows something that appears to be a contradiction in ZF:https://arweave.net/RJ4DRuRjdVWqJ5RBHB30SXDBXATzqmAV3Qs1b6f1ykw I will denote the set described by a set comprehension (more precisely, its numeric encoding, such as Godel’s encoding) X as S(X). Let M be the…… Continue reading The error in MOST logic studybooks (not in ZFC)