6 ideas
17832 | Zermelo showed that the ZF axioms in 1930 were non-categorical [Zermelo, by Hallett,M] |
13028 | Replacement was added when some advanced theorems seemed to need it [Zermelo, by Maddy] |
17626 | The antinomy of endless advance and of completion is resolved in well-ordered transfinite numbers [Zermelo] |
8923 | Numbers are identified by their main properties and relations, involving the successor function [MacBride] |
8926 | For mathematical objects to be positions, positions themselves must exist first [MacBride] |
7803 | Modal logic began with translation difficulties for 'If...then' [Lewis,CI, by Girle] |