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How are the logical connectives not, and, or, and if-then used in formal logic?

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In formal logic, specifically within the propositional calculus, logical connectives are operators used to form new propositions from existing ones. These are known as truth-functional operators because the truth value of the resulting proposition is determined solely by the truth values of its arguments.1

The four primary connectives function as follows:

  • Negation ("not," symbol ~): A monadic operator that takes one argument. The proposition ~p is true if p is false, and false if p is true.1
  • Conjunction ("and," symbol ·): A dyadic operator. The conjunction p·q is true only when both p and q are true; otherwise, it is false.1
  • Disjunction ("or," symbol ∨): A dyadic operator. The disjunction p∨q is false only when both p and q are false; it is true if at least one of the arguments is true.1
  • Conditional ("if-then," symbol ⊃): A dyadic operator representing material implication. The statement p⊃q is false only when the antecedent (p) is true and the consequent (q) is false; in all other cases, it is true.1