9 ideas
10882 | Predicative definitions only refer to entities outside the defined collection [Horsten] |
13831 | Logic is based on transitions between sentences [Prawitz] |
13825 | Natural deduction introduction rules may represent 'definitions' of logical connectives [Prawitz] |
13823 | In natural deduction, inferences are atomic steps involving just one logical constant [Prawitz] |
10884 | A theory is 'categorical' if it has just one model up to isomorphism [Horsten] |
10885 | Computer proofs don't provide explanations [Horsten] |
10881 | The concept of 'ordinal number' is set-theoretic, not arithmetical [Horsten] |
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] |