Disjunctive Syllogism: The following argument is valid: ... Any argument with the form just stated is valid. This form of argument is called a disjunctive syllogism. Basically, the argument gives you two options and says that, since one option is FALSE, the other option must be TRUE.

How do you prove disjunctive syllogism?

Proof: (related to "Disjunctive Syllogism")

The disjunctive syllogism can be formulated in propositional logic as ((p∨q)∧(¬p))⇒q. ( ( p ∨ q ) ∧ ( ¬ p ) ) ⇒ q . Therefore, by definition of a valid logical argument, the disjunctive syllogism is valid if and only if q is true, whenever both q and ¬p are true.

How do you know if a syllogism is valid?

A valid syllogism is one in which the conclu- sion must be true when each of the two premises is true; an invalid syllogism is one in which the conclusions must be false when each of the two premises is true; a neither valid nor invalid syllogism is one in which the conclusion either can be true or can be false when ...