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<b>let </b><font color="Maroon">X</font> be   <a href="subset_1.html#NM2">Subset</a> of <a href="intpro_1.html#K1" target="_self">MC-wff</a> ;<br/><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/>





<a NAME="E1:25"/>
for <font color="Olive">T</font> being  <a href="subset_1.html#NM2">Subset</a> of <a href="intpro_1.html#K1" target="_self">MC-wff</a>   st <font color="Olive">T</font> is <a href="intpro_1.html#V8" target="_self">IPC_theory</a> &amp; <font color="Maroon">X</font> <a href="tarski.html#R1">c=</a> <font color="Olive">T</font> holds <br/><span class="p1">(<span class="default"><font color="Maroon">p</font> <a href="intpro_1.html#K4" target="_self">'&amp;'</a> <font color="Maroon">q</font></span>)</span> <a href="intpro_1.html#K3" target="_self">=&gt;</a> <font color="Maroon">p</font> <a href="hidden.html#R2">in</a> <font color="Olive">T</font>
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E2:25"/>
<span class="p1">(<span class="default"><font color="Maroon">p</font> <a href="intpro_1.html#K4" target="_self">'&amp;'</a> <font color="Maroon">q</font></span>)</span> <a href="intpro_1.html#K3" target="_self">=&gt;</a> <font color="Maroon">p</font> <a href="hidden.html#R2">in</a>  <a href="intpro_1.html#K7" target="_self">CnIPC</a> <font color="Maroon">X</font>
 <b>by </b><i/>;<br/>


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