4 ideas
7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
1497 | For Anaximenes nature is air, which takes different forms by rarefaction and condensation [Anaximenes, by Simplicius] |