# Negation

From Encyclopedia of Mathematics

The logical operation as a result of which, for a given statement , the statement "not A" is obtained. In formal languages, the statement obtained as result of the negation of a statement is denoted by , , , , (these are read: "not A" , "it is not true that A" , "A does not hold" , etc.). Semantically, the negation of a statement signifies that the assumption leads to a contradiction (cf. Contradiction (inconsistency)). In classical two-valued logic the following truth table applies for the operation of negation:'

Negation. <tbody> </tbody> |

**How to Cite This Entry:**

Negation.

*Encyclopedia of Mathematics.*URL: http://www.encyclopediaofmath.org/index.php?title=Negation&oldid=18029

This article was adapted from an original article by V.E. Plisko (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article