SOLUTION: Use natural deduction to prove the following logical truth: (P ⊃ Q) ≡ [P ⊃ (Q ∨ ∼P)]

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Question 1198902: Use natural deduction to prove the following logical truth:
(P ⊃ Q) ≡ [P ⊃ (Q ∨ ∼P)]

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
(P ⊃ Q) ≡ [P ⊃ (Q ∨ ∼P)]

(~P ∨ Q) ≡ [~P ∨ (Q ∨ ~P)]  by using material implication on both sides 

(~P ∨ Q) ≡ [~P ∨ (~P ∨ Q)]  by using commutation on "(Q ∨ ∼P)"

(~P ∨ Q) ≡ [(~P ∨ ~P) ∨ Q]  by using association on the right side.

(~P ∨ Q) ≡ (~P ∨ Q)  by using the idempotent law on ~P ∨ ~P

Edwin