Compound Statement: A compound statement is a statement composed of

• one or more component statements
• at least one logical connective \([\text{~}, \wedge, \vee, \implies, \iff]\)

Tautology: A compound statement is called a tautology if it is always true for all possible combinations of truth values of its component statements.

Contradiction: A compound statement is called a contradiction if it is always false for all possible combinations of truth values of its component statements.