<?xml version="1.0"?>
<div class="add">

<b>let </b><font color="Maroon" title="c1">p</font>, <font color="Maroon" title="c2">q</font> be    <a href="subset_1.html#M2" title="SUBSET_1:mode.2">Element</a> of  <a href="cqc_lang.html#K7" title="CQC_LANG:func.7">CQC-WFF</a> ;<br/><b>let </b><font color="Maroon" title="c3">X</font> be   <a href="subset_1.html#NM2" title="SUBSET_1:NM.2">Subset</a> of <a href="cqc_lang.html#K7" title="CQC_LANG:func.7">CQC-WFF</a> ;<br/>





<b>assume </b><a NAME="E1:116"/>
<font color="Maroon" title="c3">X</font> <a href="cqc_the1.html#R3" title="CQC_THE1:pred.3">|-</a> <span class="p1">(<span class="default"><a href="cqc_lang.html#K10" title="CQC_LANG:func.10">'not'</a> <font color="Maroon" title="c1">p</font></span>)</span> <a href="cqc_lang.html#K12" title="CQC_LANG:func.12">=&gt;</a> <font color="Maroon" title="c2">q</font>
 ;<br/>

<a NAME="E2:116"/><b>then </b>
<font color="Maroon" title="c3">X</font> <a href="cqc_the1.html#R3" title="CQC_THE1:pred.3">|-</a> <span class="p1">(<span class="default"><a href="cqc_lang.html#K10" title="CQC_LANG:func.10">'not'</a> <font color="Maroon" title="c2">q</font></span>)</span> <a href="cqc_lang.html#K12" title="CQC_LANG:func.12">=&gt;</a> <font color="Maroon" title="c1">p</font>
 
<b>by </b><i><a class="ref" href="lukasi_1.html#T91" target="_self" title="LUKASI_1:th.91">Th91</a></i>;<br/>
<b>hence </b><a NAME="E3:116"/>
(  not <font color="Maroon" title="c3">X</font> <a href="cqc_the1.html#R3" title="CQC_THE1:pred.3">|-</a>  <a href="cqc_lang.html#K10" title="CQC_LANG:func.10">'not'</a> <font color="Maroon" title="c2">q</font> or <font color="Maroon" title="c3">X</font> <a href="cqc_the1.html#R3" title="CQC_THE1:pred.3">|-</a> <font color="Maroon" title="c1">p</font> )
 <b>by </b><i><a class="ref" href="cqc_the1.html#T92" title="CQC_THE1:th.92">CQC_THE1:92</a></i>;<br/>


</div>
