1904 | Proof that every set can be well-ordered |
p.4 | 15897 | Zermelo realised that Choice would facilitate the sort of 'counting' Cantor needed |
1908 | Investigations in the Foundations of Set Theory I |
p.70 | 13487 | In ZF, the Burali-Forti Paradox proves that there is no set of all ordinals |
p.107 | 15924 | Predicative definitions are acceptable in mathematics if they distinguish objects, rather than creating them? |
p.483 | 13012 | Zermelo published his axioms in 1908, to secure a controversial proof |
p.484 | 13017 | Zermelo introduced Pairing in 1930, and it seems fairly obvious |
p.484 | 13015 | Zermelo used Foundation to block paradox, but then decided that only Separation was needed |
p.485 | 13020 | The Axiom of Separation requires set generation up to one step back from contradiction |
p.489 | 13027 | Zermelo believed, and Von Neumann seemed to confirm, that numbers are sets |
Intro | p.200 | 17609 | Set theory can be reduced to a few definitions and seven independent axioms |
Intro | p.200 | 17608 | We take set theory as given, and retain everything valuable, while avoiding contradictions |
Intro | p.200 | 17607 | Set theory investigates number, order and function, showing logical foundations for mathematics |
1908 | New Proof of Possibility of Well-Ordering |
§2a | p.189 | 17613 | We should judge principles by the science, not science by some fixed principles |
1920 | works |
p.204 | 9565 | Zermelo made 'set' and 'member' undefined axioms |
p.280 | 3339 | For Zermelo's set theory the empty set is zero and the successor of each number is its unit set |
1930 | On boundary numbers and domains of sets |
§5 | p.1233 | 17626 | The antinomy of endless advance and of completion is resolved in well-ordered transfinite numbers |