document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=610046>Question 610046</A>: <I><SPAN STYLE=\"word-break: break-all;\"> my question is that i got the same conclusion as my instructor but with different methods and i was wondering if that is still ok. the instructions are to add just 2 statements to the premises to produce a formal proof of validity. ill provide my answers and his, thanks a lot. \r<BR>\n" );
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document.write( "1. (S.T) v (U.V) <BR>\n" );
document.write( "2. ~S v ~T  <BR>\n" );
document.write( "Therefore U.V \r<BR>\n" );
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document.write( "My answer \r<BR>\n" );
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document.write( "3. (U.V) v (S.t) 1, Com. <BR>\n" );
document.write( "4. U.V           3, Taut.\r<BR>\n" );
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document.write( "his answer\r<BR>\n" );
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document.write( "3. ~(S.T) 2, Dem. <BR>\n" );
document.write( "4. U.V    1,3 D.S. \r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #384097 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=384097\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Your line 4 is incorrect. A tautology is of the form p v p or p & p and they both reduce to p.\r<BR>\n" );
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document.write( "But your line 3 doesn't fit that form. So you can't use a tautology. </SPAN>\n" );
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