logically valid
1valid — adj. 1 legally acceptable VERBS ▪ be ▪ become ▪ remain, stay ▪ deem sth, hold sth ▪ …
2valid — adjective Etymology: Middle French or Medieval Latin; Middle French valide, from Medieval Latin validus, from Latin, strong, potent, from valēre Date: 1571 1. having legal efficacy or force; especially executed with the proper legal authority and …
3logically — adv. Logically is used with these adjectives: ↑coherent, ↑compatible, ↑compelling, ↑consistent, ↑equivalent, ↑impossible, ↑incompatible, ↑inconsistent, ↑independent, ↑necessary, ↑ …
4Entailment — For other uses, see Entail (disambiguation). In logic, entailment is a relation between a set of sentences (e.g.,[1] meaningfully declarative sentences or truthbearers) and a sentence. Let Γ be a set of one or more sentences; let S1 be the… …
5First-order logic — is a formal logical system used in mathematics, philosophy, linguistics, and computer science. It goes by many names, including: first order predicate calculus, the lower predicate calculus, quantification theory, and predicate logic (a less… …
6Gödel's completeness theorem — is a fundamental theorem in mathematical logic that establishes a correspondence between semantic truth and syntactic provability in first order logic. It was first proved by Kurt Gödel in 1929. A first order formula is called logically valid if… …
7Propositional calculus — In mathematical logic, a propositional calculus or logic (also called sentential calculus or sentential logic) is a formal system in which formulas of a formal language may be interpreted as representing propositions. A system of inference rules… …
8Problem of evil — Part of a series on God General conceptions …
9Interpretation (logic) — An interpretation is an assignment of meaning to the symbols of a formal language. Many formal languages used in mathematics, logic, and theoretical computer science are defined in solely syntactic terms, and as such do not have any meaning until …
10Rationality — as a term is related to the idea of reason, a word which following Webster s may be derived as much from older terms referring to thinking itself as from giving an account or an explanation. This lends the term a dual aspect. One aspect… …
