5 ideas
9987 | An aggregate in which order does not matter I call a 'set' [Bolzano] |
8920 | Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz] |
10856 | A truly infinite quantity does not need to be a variable [Bolzano] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |