8 ideas
9540 | A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell] |
9541 | The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell] |
9543 | The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell] |
9544 | A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell] |
21354 | It may be that internal relations like proportion exist, because we directly perceive it [MacBride] |
21353 | Internal relations are fixed by existences, or characters, or supervenience on characters [MacBride] |
21352 | 'Multigrade' relations are those lacking a fixed number of relata [MacBride] |
22489 | 'Good' is an attributive adjective like 'large', not predicative like 'red' [Geach, by Foot] |