<logic> The state of being true or the state of being false.
Logics in which there are only two truth-values, namely, truth and falsehood.
Logics that recognize more than two truth-values. In 3-valued logics, for example, the third truth-value is often "unknown" or "unprovable" or "neither true nor false". Also called n-valued logics.
[Glossary of First-Order Logic]
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