document.write( "Question 1195749: Phil 10\r
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Algebra.Com's Answer #828362 by mccravyedwin(407) $\"\"$ $\"About$

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document.write( "/ ∴ P ⊃ P\r\n" );
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document.write( "               |1. ~(P ⊃ P)         Assumption for indirect proof\r\n" );
document.write( "               |2. ~(~P v P)         1, Material implication     \r\n" );
document.write( "               |3. ~~P • ~P          2, DeMorgan's law\r\n" );
document.write( "               |4. P • ~P            3, Double negation\r\n" );
document.write( "5. P ⊃ P           lines 1-4     Indirect proof\r\n" );
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document.write( "Edwin

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