Namespaces
Variants
Actions

Logical law

From Encyclopedia of Mathematics
Revision as of 13:21, 9 April 2014 by Ivan (talk | contribs) (TeX)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

in mathematical logic

A logical formula that becomes a true proposition under any interpretation of the variables for propositions and predicates that occur in it. Such formulas are called generally valid, universally valid or tautologies. For example, the tautology $A\lor\neg A$ expresses the law of the excluded middle.


Comments

References

[a1] A. Grzegorczyk, "An outline of mathematical logic" , Reidel (1974)
How to Cite This Entry:
Logical law. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Logical_law&oldid=18440
This article was adapted from an original article by V.E. Plisko (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article