Tautology (rule of inference)

In logic, a **tautology** is a statement or formula that is true in every possible interpretation, regardless of the truth values of its components. In other words, it is a logical expression that cannot be false. Tautologies are important in propositional logic and are often used as the basis for proving other statements. One common example of a tautology is the expression \( p \lor \neg p \) (where \( p \) is any proposition).