document.write( "Question 1000819: 1. ~P>[~P>(Q>P)]
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Algebra.Com's Answer #618492 by Edwin McCravy(20054)\"\" \"About 
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document.write( "1. ~P>[~P>(Q>P)]\r\n" );
document.write( "2. ~P                / :. ~Q\r\n" );
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document.write( "3. ~P>(Q>P)       1,2, modus ponens\r\n" );
document.write( "4. Q>P            3,2, modus ponens\r\n" );
document.write( "5. ~Q             4,2, modus tollens\r\n" );
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document.write( "Edwin
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