3 ideas
9355 | One sort of circularity presupposes a premise, the other presupposes a rule being used [Braithwaite, by Devitt] |
8942 | Lukasiewicz's L3 logic has three truth-values, T, F and I (for 'indeterminate') [Lukasiewicz, by Fisher] |
17699 | Variables are auxiliary notions, and not part of the 'eternal' essence of logic [Schönfinkel] |