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

<b>let </b><font color="Maroon">c<sub>1</sub></font> be  non <a href="struct_0.html#V3">empty</a> <a href="pre_topc.html#NM1">TopSpace</a>;<br/><b>let </b><font color="Maroon">c<sub>2</sub></font>, <font color="Maroon">c<sub>3</sub></font> be   <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">c<sub>1</sub></font>;<br/>





<b>assume </b><a NAME="E1:2"/>
( <font color="Maroon">c<sub>2</sub></font> is <a href="tops_3.html#V1">everywhere_dense</a> &amp; <font color="Maroon">c<sub>3</sub></font> is <a href="tops_3.html#V1">everywhere_dense</a> )
 ;<br/>

<a NAME="E2:2"/><b>then </b>
<font color="Maroon">c<sub>2</sub></font> <a href="subset_1.html#K9">/\</a> <font color="Maroon">c<sub>3</sub></font> is <a href="tops_3.html#V1">everywhere_dense</a>
 
<b>by </b><i><a class="ref" href="tops_3.html#T44">TOPS_3:44</a></i>;<br/>
<a NAME="E3:2"/><b>then </b>
<font color="Maroon">c<sub>2</sub></font> <a href="subset_1.html#K9">/\</a> <font color="Maroon">c<sub>3</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 
<b>by </b><i><a class="ref" href="tops_3.html#T34">TOPS_3:34</a></i>;<br/>
<b>hence </b><a NAME="E4:2"/>
<font color="Maroon">c<sub>2</sub></font> <a href="xboole_0.html#NR5" target="_self">meets</a> <font color="Maroon">c<sub>3</sub></font>
 <b>by </b><i><a class="ref" href="xboole_0.html#D7">XBOOLE_0:def 7</a></i>;<br/>


</div>
