4 ideas
9565 | Zermelo made 'set' and 'member' undefined axioms [Zermelo, by Chihara] |
3339 | For Zermelo's set theory the empty set is zero and the successor of each number is its unit set [Zermelo, by Blackburn] |
14963 | Surely the past phases of a thing are not parts of the thing? [Broad] |
1558 | Clearly the gods ignore human affairs, or they would have given us justice [Thrasymachus] |