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<b>let </b><font color="Maroon">p</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="intpro_1.html#K1" target="_self">MC-wff</a> ;<br/><b>let </b><font color="Maroon">q</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="intpro_1.html#K1" target="_self">MC-wff</a> ;<br/>



<b>assume </b><a NAME="E1:97"/><i><font color="Green">E26</font></i>: 
( <font color="Maroon">p</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a>  or <font color="Maroon">q</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a>  )
 ;<br/>

<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="97_1"><b>now </b></a><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="97_1_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:97_1_1"/>
( <font color="Maroon">p</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a>  or <font color="Maroon">q</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a>  )
 </span><b>by </b><i><a class="ref" href="intpro_1.html#T1" target="_self">Th1</a></i>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="97_1_1_1"><b>case </b></a><a NAME="E1:97_1_1_1"/><i><font color="Green">E28</font></i>: 
<font color="Maroon">p</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a> 
 ;<br/><div class="add"><a NAME="E2:97_1_1_1"/>
<font color="Maroon">p</font> <a href="intpro_1.html#K3" target="_self">=&gt;</a> <span class="p1">(<span class="default"><font color="Maroon">p</font> <a href="intpro_1.html#K5" target="_self">'or'</a> <font color="Maroon">q</font></span>)</span> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a> 
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E3:97_1_1_1"/>
<font color="Maroon">p</font> <a href="intpro_1.html#K5" target="_self">'or'</a> <font color="Maroon">q</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a> 
 <b>by </b><i><a class="ref" href="intpro_1.html#T2" target="_self">Th2</a>, </i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="97_1_1_2"><b>case </b></a><a NAME="E1:97_1_1_2"/><i><font color="Green">E29</font></i>: 
<font color="Maroon">q</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a> 
 ;<br/><div class="add"><a NAME="E2:97_1_1_2"/>
<font color="Maroon">q</font> <a href="intpro_1.html#K3" target="_self">=&gt;</a> <span class="p1">(<span class="default"><font color="Maroon">p</font> <a href="intpro_1.html#K5" target="_self">'or'</a> <font color="Maroon">q</font></span>)</span> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a> 
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E3:97_1_1_2"/>
<font color="Maroon">p</font> <a href="intpro_1.html#K5" target="_self">'or'</a> <font color="Maroon">q</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a> 
 <b>by </b><i><a class="ref" href="intpro_1.html#T2" target="_self">Th2</a>, </i>;<br/></div><b>end;</b></div></div><b>end;</b></div></div><b>end;</b></div>
<b>hence </b><a NAME="E3:97"/>
<font color="Maroon">p</font> <a href="intpro_1.html#K5" target="_self">'or'</a> <font color="Maroon">q</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K8" target="_self">IPC-Taut</a> 
 ;<br/>


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