display all the ideas for this combination of texts
4 ideas
13342 | Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap] |
8078 | Modus ponens is one of five inference rules identified by the Stoics [Chrysippus, by Devlin] |
13251 | Each person is free to build their own logic, just by specifying a syntax [Carnap] |
6023 | Every proposition is either true or false [Chrysippus, by Cicero] |