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

<b>let </b><font color="Maroon">g</font> be   <a href="closure2.html#NM3">SetOp</a> of <font color="Maroon">M</font>;<br/>

<b>assume </b><a NAME="E1:61_1_1"/><i><font color="Green">E36</font></i>: 
<font color="Maroon">g</font> is <a href="closure2.html#V10" target="_self">topological</a>
 ;<br/>

<b>let </b><font color="Maroon">X</font> be    <a href="closure2.html#M1" target="_self">Element</a> of  <a href="closure2.html#K6" target="_self">Bool</a> <font color="Maroon">M</font>, <font color="Maroon">Y</font> be    <a href="closure2.html#M1" target="_self">Element</a> of  <a href="closure2.html#K6" target="_self">Bool</a> <font color="Maroon">M</font>; <i><font color="Red">:: according to </font></i><a class="ref" href="closure2.html#D13" target="_self">CLOSURE2:def 13</a><br/>

<b>assume </b><a NAME="E2:61_1_1"/><i><font color="Green">E39</font></i>: 
<font color="Maroon">X</font> <a href="pboole.html#R2">c=</a> <font color="Maroon">Y</font>
 ;<br/>

<span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="closure2.html#K7" target="_self">.</a> <font color="Maroon">X</font></span>)</span> <a href="pboole.html#K2">\/</a> <span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="closure2.html#K7" target="_self">.</a> <font color="Maroon">Y</font></span>)</span> = 
<font color="Maroon">g</font> <a href="funct_1.html#K1">.</a> <span class="p1">(<span class="default"><font color="Maroon">X</font> <a href="pboole.html#K2">\/</a> <font color="Maroon">Y</font></span>)</span>
<b>by </b><i>, </i>
<br/>.= 
<font color="Maroon">g</font> <a href="closure2.html#K7" target="_self">.</a> <font color="Maroon">Y</font>
<b>by </b><i>, <a class="ref" href="pboole.html#T24">PBOOLE:24</a></i>
;<br/>
<b>hence </b><a NAME="E4:61_1_1"/>
<font color="Maroon">g</font> <a href="closure2.html#K7" target="_self">.</a> <font color="Maroon">X</font> <a href="pboole.html#R2">c=</a> <font color="Maroon">g</font> <a href="closure2.html#K7" target="_self">.</a> <font color="Maroon">Y</font>
 <b>by </b><i><a class="ref" href="pboole.html#T28">PBOOLE:28</a></i>;<br/>


</div>
