24 ideas
7786 | Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle] |
7798 | There are three axiom schemas for propositional logic [Girle] |
7799 | Proposition logic has definitions for its three operators: or, and, and identical [Girle] |
7797 | Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle] |
7794 | There are seven modalities in S4, each with its negation [Girle] |
7793 | ◊p → □◊p is the hallmark of S5 [Girle] |
7795 | S5 has just six modalities, and all strings can be reduced to those [Girle] |
7787 | Possible worlds logics use true-in-a-world rather than true [Girle] |
7788 | Modal logic has four basic modal negation equivalences [Girle] |
7796 | Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle] |
7789 | Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle] |
10061 | The If-thenist view only seems to work for the axiomatised portions of mathematics [Musgrave] |
10065 | Perhaps If-thenism survives in mathematics if we stick to first-order logic [Musgrave] |
7790 | If an argument is invalid, a truth tree will indicate a counter-example [Girle] |
10049 | Logical truths may contain non-logical notions, as in 'all men are men' [Musgrave] |
10050 | A statement is logically true if it comes out true in all interpretations in all (non-empty) domains [Musgrave] |
10058 | No two numbers having the same successor relies on the Axiom of Infinity [Musgrave] |
10062 | Formalism seems to exclude all creative, growing mathematics [Musgrave] |
10063 | Formalism is a bulwark of logical positivism [Musgrave] |
12887 | A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim] |
7800 | Analytic truths are divided into logically and conceptually necessary [Girle] |
7801 | Possibilities can be logical, theoretical, physical, economic or human [Girle] |
7792 | A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle] |
10060 | Logical positivists adopted an If-thenist version of logicism about numbers [Musgrave] |