See Also: Tautology(medicine)
tautology(dictionary)
tautology(encyclopedia)
tautology(dictionary)

tautology (sh)




In logic, a statement that cannot be denied without inconsistency.

Thus, "All bachelors are either male or not male" is held to assert, with regard to anything whatsoever that is a bachelor, that it is male or it is not male. In the propositional calculus, even complicated symbolic expressions such as [(A ? B) กฤ (C ? ? B)] ? (C ? ? A) can be shown to be tautologies by displaying in a truth table every possible combination of T (true) and F (false) of its arguments A, B, C. A tautology can be purely formal (a statement form rather than a statement), and in some usages only such formal truths are tautologies.