display all the ideas for this combination of texts
4 ideas
15926 | Second-order logic presupposes a set of relations already fixed by the first-order domain [Lavine] |
8078 | Modus ponens is one of five inference rules identified by the Stoics [Chrysippus, by Devlin] |
6023 | Every proposition is either true or false [Chrysippus, by Cicero] |
15934 | Mathematical proof by contradiction needs the law of excluded middle [Lavine] |