document.write( "Question 1200104: When using rules of implication for natural deduction, how would I get to my next steps after the following:
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Algebra.Com's Answer #834128 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "1.(R>L)>(L>~F)\r\n" );
document.write( "2. ~F v (R>L)\r\n" );
document.write( "3. ~~F /~R\r\n" );
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document.write( "4. R>L         2,3, Disjunctive Syllogism  ---That's [(p v q) & ~p]>q\r\n" );
document.write( "5. L>~F        1,4, Modus Ponens           ---That's [(p>q) & p]>q\r\n" );
document.write( "6. R>~F        4,5, Hypothetical Syllogism ---That's [(p>q) & (q>r)]>(p>r)\r\n" );
document.write( "7. ~R          6,3, Modus tollens          ---That's [(p>q) & ~q]>~p \r\n" );
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document.write( "They're all common sense if you think about it and think about them in words\r\n" );
document.write( " using \"the first\", \"the second\" and \"the third\", like this:\r\n" );
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document.write( "Disjunctive Syllogism says: [(p v q) & ~p]>q\r\n" );
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document.write( "If you know that (you have the first OR the second) AND (you do NOT have the\r\n" );
document.write( "first), then you MUST have (the second). \r\n" );
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document.write( "I think of \" > \" as the same as the word \"guarantees\".\r\n" );
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document.write( "Modus Ponens says: [(p>q) & p]>q\r\n" );
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document.write( "If you know that (the first guarantees the second), AND you know that you have\r\n" );
document.write( "(the first), then you MUST have (the second).\r\n" );
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document.write( "Hypothetical Syllogism says: [(p>q) & (q>r)]>(p>r)\r\n" );
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document.write( "If you know that (the first guarantees the second) AND (the second guarantees\r\n" );
document.write( "the third), then (the first MUST guarantee the third).\r\n" );
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document.write( "Modus Tollens says: [(p>q) & ~q]>~p \r\n" );
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document.write( "If you know that (the first guarantees the second) and (you do NOT have the\r\n" );
document.write( "second), then (you MUST NOT have the first).\r\n" );
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document.write( "Edwin
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