document.write( "Question 1198902: Use natural deduction to prove the following logical truth:
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Algebra.Com's Answer #832909 by Edwin McCravy(20056)\"\" \"About 
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document.write( "(P ⊃ Q) ≡ [P ⊃ (Q ∨ ∼P)]\r\n" );
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document.write( "(~P ∨ Q) ≡ [~P ∨ (Q ∨ ~P)]  by using material implication on both sides \r\n" );
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document.write( "(~P ∨ Q) ≡ [~P ∨ (~P ∨ Q)]  by using commutation on \"(Q ∨ ∼P)\"\r\n" );
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document.write( "(~P ∨ Q) ≡ [(~P ∨ ~P) ∨ Q]  by using association on the right side.\r\n" );
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document.write( "(~P ∨ Q) ≡ (~P ∨ Q)  by using the idempotent law on ~P ∨ ~P\r\n" );
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document.write( "Edwin

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