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<b>let </b><font color="Maroon">S1</font> be    <a href="subset_1.html#M2">Element</a> of  <a href="substut1.html#K38">CQC-Sub-WFF</a> ;<br/><b>let </b><font color="Maroon">S2</font> be    <a href="subset_1.html#M2">Element</a> of  <a href="substut1.html#K38">CQC-Sub-WFF</a> ;<br/>



<b>assume </b><a NAME="E1:31"/><i><font color="Green">E55</font></i>: 
<font color="Maroon">S1</font> <a href="substut1.html#K19">`2</a>  <a href="hidden.html#R1">=</a> <font color="Maroon">S2</font> <a href="substut1.html#K19">`2</a> 
 ;<br/>

<a NAME="E2:31"/><b>then </b>
 <a href="sublemma.html#K7" target="_self">CQCSub_&amp;</a> <font color="Maroon">S1</font>,<font color="Maroon">S2</font> <a href="hidden.html#R1">=</a>  <a href="substut1.html#K21">Sub_&amp;</a> <font color="Maroon">S1</font>,<font color="Maroon">S2</font>
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E3:31"/>
 <a href="substut1.html#K39">CQC_Sub</a> <span class="p1">(<span class="default"><a href="sublemma.html#K7" target="_self">CQCSub_&amp;</a> <font color="Maroon">S1</font>,<font color="Maroon">S2</font></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="substut1.html#K39">CQC_Sub</a> <font color="Maroon">S1</font></span>)</span> <a href="cqc_lang.html#K11">'&amp;'</a> <span class="p1">(<span class="default"><a href="substut1.html#K39">CQC_Sub</a> <font color="Maroon">S2</font></span>)</span>
 <b>by </b><i>, <a class="ref" href="substut1.html#T31">SUBSTUT1:31</a></i>;<br/>


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