Negation

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:'

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