document.write( "Question 1171799: Use the inference rules to derive the conclusion\r
\n" ); document.write( "\n" ); document.write( "1. T ⊃ O
\n" ); document.write( "2. R v ~O
\n" ); document.write( "3. ~R/~T
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #797531 by Edwin McCravy(20054)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "1. T ⊃ O\r\n" );
document.write( "2. R v ~O\r\n" );
document.write( "3. ~R              /~T\r\n" );
document.write( "\r\n" );
document.write( "4. ~O            2,3 Disjunctive Syllogism | You Must Learn: [(p v q) & ~p] ⊃ q\r\n" );
document.write( "5. ~T            1,5 Modus tollens         | You Must Learn: [(p ⊃ q) & ~q] ⊃ p\r\n" );
document.write( "\r\n" );
document.write( "It's common sense that if you know one of two things is true, then if one of them\r\n" );
document.write( "is not true, then the other one must be true.  That's disjunctive syllogism!\r\n" );
document.write( "\r\n" );
document.write( "It's also common sense that if a first thing implies a second thing, and the\r\n" );
document.write( "second thing is not true, then the first thing must not have been true either.\r\n" );
document.write( "That's modus tollens.\r\n" );
document.write( "\r\n" );
document.write( "All logic is plain old common sense.  You just have to learn what it says.\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );