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<b>let </b><font color="Maroon">I</font> be    <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">M</font> be  <a href="relat_1.html#V2">V5</a>  <a href="pboole.html#M1">ManySortedSet</a> of <font color="Maroon">I</font>;<br/><b>let </b><font color="Maroon">X</font> be    <a href="pboole.html#M2">Element</a> of <font color="Maroon">M</font>, <font color="Maroon">Y</font> be    <a href="pboole.html#M2">Element</a> of <font color="Maroon">M</font>;<br/>





<b>assume </b><a NAME="E1:17"/><i><font color="Green">E34</font></i>: 
<font color="Maroon">X</font> <a href="pboole.html#R2">c=</a> <font color="Maroon">Y</font>
 ;<br/>

<a NAME="E2:17"/>
( <span class="p1">(<span class="default"><a href="msualg_3.html#K2">id</a> <font color="Maroon">M</font></span>)</span> <a href="closure1.html#K2" target="_self">..</a> <font color="Maroon">X</font> <a href="pboole.html#R6">=</a> <font color="Maroon">X</font> &amp; <span class="p1">(<span class="default"><a href="msualg_3.html#K2">id</a> <font color="Maroon">M</font></span>)</span> <a href="closure1.html#K2" target="_self">..</a> <font color="Maroon">Y</font> <a href="pboole.html#R6">=</a> <font color="Maroon">Y</font> )
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E3:17"/>
<span class="p1">(<span class="default"><a href="msualg_3.html#K2">id</a> <font color="Maroon">M</font></span>)</span> <a href="closure1.html#K2" target="_self">..</a> <font color="Maroon">X</font> <a href="pboole.html#R2">c=</a> <span class="p1">(<span class="default"><a href="msualg_3.html#K2">id</a> <font color="Maroon">M</font></span>)</span> <a href="closure1.html#K2" target="_self">..</a> <font color="Maroon">Y</font>
 <b>by </b><i/>;<br/>


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