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

<b>reconsider </b><font color="Maroon">A</font> = <font color="Maroon">P</font>, <font color="Maroon">B</font> = <font color="Maroon">Q</font> as   <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">T</font> ;<br/>
<a NAME="E2:6_2_1"/>
( <font color="Maroon">A</font> is <a href="pre_topc.html#V3">open</a> &amp; <font color="Maroon">B</font> is <a href="pre_topc.html#V3">open</a> )
 
<b>by </b><i/>;<br/>
<a NAME="E3:6_2_1"/><b>then </b>
<font color="Maroon">P</font> <a href="subset_1.html#K9">/\</a> <font color="Maroon">Q</font> is <a href="pre_topc.html#V3">open</a>
 
<b>by </b><i><a class="ref" href="tops_1.html#T38">TOPS_1:38</a></i>;<br/>
<b>hence </b><a NAME="E4:6_2_1"/>
<font color="Maroon">P</font> <a href="xboole_0.html#K3">/\</a> <font color="Maroon">Q</font> is    <a href="subset_1.html#M2">Element</a> of  <a href="openlatt.html#K1" target="_self">Topology_of</a> <font color="Maroon">T</font>
 <b>by </b><i/>;<br/>


</div>
