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

<b>consider </b><font color="Maroon" title="c2">F</font> being  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a> <a href="struct_0.html#NM3" title="STRUCT_0:NM.3">Subset-Family</a> of <font color="Maroon" title="c1">T</font>;<br/>
<a NAME="E2:36_1_1"/>
<font color="Maroon" title="c2">F</font> is <a href="tops_2.html#V1" title="TOPS_2:attr.1">open</a>
 
;<br/>
<b>hence </b><a NAME="E3:36_1_1"/>
 ex <font color="Olive">b<sub>1</sub></font> being  <a href="struct_0.html#NM3" title="STRUCT_0:NM.3">Subset-Family</a> of <font color="Maroon" title="c1">T</font> st <br/>( <font color="Olive">b<sub>1</sub></font> is <a href="card_4.html#V1" title="CARD_4:attr.1">countable</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="tops_2.html#V1" title="TOPS_2:attr.1">open</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="tops_2.html#V2" title="TOPS_2:attr.2">closed</a> )
 ; <a class="txt" onclick="hs(this)" href="javascript:()"><i><font color="Red">::  thesis: </font></i></a><span class="hide"> verum</span><br/>


</div>
