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<b>let </b><font color="Maroon" title="c1">p1</font>, <font color="Maroon" title="c2">p2</font> be    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="qc_lang1.html#K8" title="QC_LANG1:func.8">QC-WFF</a> ;<br/><b>let </b><font color="Maroon" title="c3">x1</font>, <font color="Maroon" title="c4">x2</font>, <font color="Maroon" title="c5">y1</font>, <font color="Maroon" title="c6">y2</font> be   <a href="qc_lang1.html#NM3" title="QC_LANG1:NM.3">bound_QC-variable</a>;<br/>





<b>assume </b><a NAME="E1:16"/><i><font color="Green" title="E12">A1</font></i>: 
 <a href="qc_lang2.html#K6" title="QC_LANG2:func.6">All</a> <font color="Maroon" title="c3">x1</font>,<font color="Maroon" title="c5">y1</font>,<font color="Maroon" title="c1">p1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang2.html#K6" title="QC_LANG2:func.6">All</a> <font color="Maroon" title="c4">x2</font>,<font color="Maroon" title="c6">y2</font>,<font color="Maroon" title="c2">p2</font>
 ;<br/>

<a NAME="E2:16"/><i><font color="Green" title="E13">A2</font></i>: 
 <a href="qc_lang1.html#K14" title="QC_LANG1:func.14">All</a> <font color="Maroon" title="c3">x1</font>,<span class="p1">(<span class="default"><a href="qc_lang1.html#K14" title="QC_LANG1:func.14">All</a> <font color="Maroon" title="c5">y1</font>,<font color="Maroon" title="c1">p1</font></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang1.html#K14" title="QC_LANG1:func.14">All</a> <font color="Maroon" title="c4">x2</font>,<span class="p1">(<span class="default"><a href="qc_lang1.html#K14" title="QC_LANG1:func.14">All</a> <font color="Maroon" title="c6">y2</font>,<font color="Maroon" title="c2">p2</font></span>)</span>
 
<b>by </b><i><a class="txt" href="qc_lang2.html#E1:16"><i><font color="Green" title="E12">A1</font></i></a></i>;<br/>
<b>hence </b><a NAME="E3:16"/>
<font color="Maroon" title="c3">x1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c4">x2</font>
 <b>by </b><i><a class="ref" href="qc_lang2.html#T6" target="_self" title="QC_LANG2:th.6">Th6</a></i>;<br/>

<a NAME="E4:16"/>
 <a href="qc_lang1.html#K14" title="QC_LANG1:func.14">All</a> <font color="Maroon" title="c5">y1</font>,<font color="Maroon" title="c1">p1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang1.html#K14" title="QC_LANG1:func.14">All</a> <font color="Maroon" title="c6">y2</font>,<font color="Maroon" title="c2">p2</font>
 
<b>by </b><i><a class="txt" href="qc_lang2.html#E2:16"><i><font color="Green" title="E13">A2</font></i></a>, <a class="ref" href="qc_lang2.html#T6" target="_self" title="QC_LANG2:th.6">Th6</a></i>;<br/>
<b>hence </b><a NAME="E5:16"/>
( <font color="Maroon" title="c5">y1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">y2</font> &amp; <font color="Maroon" title="c1">p1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">p2</font> )
 <b>by </b><i><a class="ref" href="qc_lang2.html#T6" target="_self" title="QC_LANG2:th.6">Th6</a></i>;<br/>


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