4 ideas
8920 | Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz] |
17319 | There are 'conceptual' explanations, with their direction depending on complexity [Schnieder] |
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] |