Given the argument: K ∨ E / E ⊃ ∼ K // K ≡ ∼ E This argument is: A) Invalid; fails in 2^nd line. B) Valid. C) Invalid; fails in 1^st line. D) Invalid; fails in 4^th line. E) Invalid; fails in 3^rd line.

Question

Quizplus · Accepted Answer

The argument is valid because it is a syllogism with a valid form. The first premise is a disjunction, the second premise is a conditional, and the conclusion is an equivalence. The form of the argument is:```P ∨ QQ ⊃ R∴ P ≡ R```This form of argument is valid because if the first premise is true, then either P or Q is true. If the second premise is true, then if Q is true, then R is true. Therefore, if the first premise and the second premise are both true, then either P is true or R is true. This is equivalent to saying that P and R are equivalent.

Given the Argument: K ∨ E / E ⊃ ∼