|General validity: within a calculus a formula that is satisfied by any interpretation (variable assignment with expressions for objects) is valid. See also satisfaction, satisfiability, interpretation._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments. |
|Hughes I 65ff
Validity/Hughes/Cresswell: No structural property of formulas, no relation between formulas. - In contrast: derivability relation between formulas. - Yet the set of the derived and the valid formulas in a system are identical.
Hughes I 119
Validity/propositional calculus: truth tables are not sufficient for an evaluation of formulas in the propositional calculus. - Because we can not assign truth values to individual variables and predicate variables._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.
M. J. Cresswell
Semantical Essays (Possible worlds and their rivals) Dordrecht Boston 1988
M. J. Cresswell
Structured Meanings Cambridge Mass. 1984
Maxwell J. Cresswell
Einführung in die Modallogik Berlin New York 1978