Statements {analytic statement} can be true because subject and object meanings are the same, or one is part of other. Using general logical laws and definitions, denying analytic statements leads to contradiction, so analytic statements are logically necessary.
Statements {necessary truth}| can be true and cannot be false, like arithmetical equalities.
Statements {tautology}| {valid formula} can be true in themselves, without reference to anything else. Tautologies are true for any term or predicate substitutions. Tautologies have necessary and sufficient conditions. Tautologies depend on accepted definitions. The opposite of tautology is self-contradictory.
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Date Modified: 2022.0225