送交者: steven 于 2005-9-14, 16:24:01:
回答: 好吧，我来回答。如果说的不对你再来讲。 由 bluesea 于 2005-9-14, 15:08:32:
what you are talking about.First, if you meant Liar's paradox (谎言逻辑) like: this statement is false, it is not by Russell. Russell's paradox is related to second-order logic, and it shows that the Ferge system is too board, and it is by itself inconsistent. To fix this problem, logicans restricted Ferge sytem into what we calls first-order logic today. This requires adding axioms to the system. However, Godel showed that even with axiom, first-order logic still not complete.
There isn't anything that First-order Logics 遗留的问题 that can be solved in modal-logic or temporal logic. As a matter of fact, the later are more restricted and cover less than first-order logic.