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

<b>let </b><font color="Maroon">T</font> be   <a href="pre_topc.html#NM1">TopSpace</a>;<br/><b>let </b><font color="Maroon">F</font> be  <a href="finset_1.html#V1">finite</a> <a href="struct_0.html#NM3">Subset-Family</a> of <font color="Maroon">T</font>;<br/>



<b>assume </b><a NAME="E1:22"/><i><font color="Green">E56</font></i>: 
for <font color="Olive">X</font> being  <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">T</font>  st <font color="Olive">X</font> <a href="hidden.html#R2">in</a> <font color="Maroon">F</font> holds <br/><font color="Olive">X</font> is <a href="compts_1.html#V6">compact</a>
 ;<br/>

<b>defpred </b><font color="Maroon">S<sub>1</sub></font>[   <a href="hidden.html#M1">set</a> ] <b>means </b> ex <font color="Olive">A</font> being  <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">T</font> st <br/>( <font color="Olive">A</font> <a href="hidden.html#R1">=</a>  <a href="tarski.html#K3">union</a> <font color="Maroon">a<sub>1</sub></font> &amp; <font color="Olive">A</font> is <a href="compts_1.html#V6">compact</a> );<br/>
<a NAME="E2:22"/><i><font color="Green">E57</font></i>: 
<font color="Maroon">F</font> is <a href="finset_1.html#V1">finite</a>
 
;<br/>
<a NAME="E3:22"/><i><font color="Green">E58</font></i>: 
<font color="Maroon">S<sub>1</sub></font>[ <a href="xboole_0.html#K1">{}</a> ]
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="22_1"><b>proof </b></a><div class="add">

<b>take </b>
 <a href="pre_topc.html#K1">{}</a> <font color="Maroon">T</font>
;<br/>

<b>thus </b><a NAME="E1:22_1"/>
(  <a href="pre_topc.html#K1">{}</a> <font color="Maroon">T</font> <a href="hidden.html#R1">=</a>  <a href="tarski.html#K3">union</a> <a href="xboole_0.html#K1">{}</a>  &amp;  <a href="pre_topc.html#K1">{}</a> <font color="Maroon">T</font> is <a href="compts_1.html#V6">compact</a> )
 <b>by </b><i><a class="ref" href="zfmisc_1.html#T2">ZFMISC_1:2</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E4:22"/><i><font color="Green">E59</font></i>: 
for <font color="Olive">x</font>, <font color="Olive">B</font> being   <a href="hidden.html#M1">set</a>   st <font color="Olive">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">F</font> &amp; <font color="Olive">B</font> <a href="tarski.html#R1">c=</a> <font color="Maroon">F</font> &amp; <font color="Maroon">S<sub>1</sub></font>[<font color="Olive">B</font>] holds <br/><font color="Maroon">S<sub>1</sub></font>[<font color="Olive">B</font> <a href="xboole_0.html#K2">\/</a> <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><font color="Olive">x</font></span><a href="tarski.html#K1">}</a></span>]
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="22_2"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">x</font> be    <a href="hidden.html#M1">set</a> , <font color="Maroon">B</font> be    <a href="hidden.html#M1">set</a> ;<br/>

<b>assume </b><b>that </b><br/><a NAME="E1:22_2"/><i><font color="Green">E66</font></i>: 
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">F</font>
 <b>and </b><br/><a NAME="E2:22_2"/><i><font color="Green">E67</font></i>: 
<font color="Maroon">B</font> <a href="tarski.html#R1">c=</a> <font color="Maroon">F</font>
 ;<br/>

<b>given </b><font color="Maroon">A</font> being   <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">T</font><b> such that </b><a NAME="E3:22_2"/><i><font color="Green">E69</font></i>: 
<font color="Maroon">A</font> <a href="hidden.html#R1">=</a>  <a href="tarski.html#K3">union</a> <font color="Maroon">B</font>
 <b>and </b><br/><a NAME="E4:22_2"/><i><font color="Green">E70</font></i>: 
<font color="Maroon">A</font> is <a href="compts_1.html#V6">compact</a>
 ;<br/>

<b>reconsider </b><font color="Maroon">X</font> = <font color="Maroon">x</font> as   <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">T</font> <b>by </b><i/>;<br/>
<a NAME="E6:22_2"/>
<font color="Maroon">B</font> <a href="tarski.html#R1">c=</a>  <a href="pcomps_1.html#K1">bool</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">T</font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="22_2_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">b</font> be    <a href="hidden.html#M1">set</a> ; <i><font color="Red">:: according to </font></i><a class="ref" href="tarski.html#D3">TARSKI:def 3</a><br/>

<b>assume </b><a NAME="E1:22_2_1"/>
<font color="Maroon">b</font> <a href="hidden.html#R2">in</a> <font color="Maroon">B</font>
 ;<br/>

<a NAME="E2:22_2_1"/><b>then </b>
<font color="Maroon">b</font> <a href="hidden.html#R2">in</a> <font color="Maroon">F</font>
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E3:22_2_1"/>
<font color="Maroon">b</font> <a href="hidden.html#R2">in</a>  <a href="pcomps_1.html#K1">bool</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">T</font>
 ;<br/>


</div><b>end;</b></div>
<b>then reconsider </b><font color="Maroon">C</font> = <font color="Maroon">B</font> as   <a href="struct_0.html#NM3">Subset-Family</a> of <font color="Maroon">T</font> ;<br/>
<b>set </b><font color="Maroon">K</font> = <span class="p1">(<span class="default"><a href="setfam_1.html#K5">union</a> <font color="Maroon">C</font></span>)</span> <a href="subset_1.html#K4">\/</a> <font color="Maroon">X</font>;<br/>
<b>take </b>
<span class="p1">(<span class="default"><a href="setfam_1.html#K5">union</a> <font color="Maroon">C</font></span>)</span> <a href="subset_1.html#K4">\/</a> <font color="Maroon">X</font>
;<br/>

<a NAME="E8:22_2"/>
 <a href="tarski.html#K3">union</a> <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><font color="Maroon">x</font></span><a href="tarski.html#K1">}</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">x</font>
 
<b>by </b><i><a class="ref" href="zfmisc_1.html#T31">ZFMISC_1:31</a></i>;<br/>
<b>hence </b><a NAME="E9:22_2"/>
<span class="p1">(<span class="default"><a href="setfam_1.html#K5">union</a> <font color="Maroon">C</font></span>)</span> <a href="subset_1.html#K4">\/</a> <font color="Maroon">X</font> <a href="hidden.html#R1">=</a>  <a href="tarski.html#K3">union</a> <span class="p1">(<span class="default"><font color="Maroon">B</font> <a href="xboole_0.html#K2">\/</a> <span class="p2"><a href="tarski.html#K1">{</a><span class="default"><font color="Maroon">x</font></span><a href="tarski.html#K1">}</a></span></span>)</span>
 <b>by </b><i><a class="ref" href="zfmisc_1.html#T96">ZFMISC_1:96</a></i>;<br/>

<a NAME="E10:22_2"/>
<font color="Maroon">X</font> is <a href="compts_1.html#V6">compact</a>
 
<b>by </b><i>, </i>;<br/>
<b>hence </b><a NAME="E11:22_2"/>
<span class="p1">(<span class="default"><a href="setfam_1.html#K5">union</a> <font color="Maroon">C</font></span>)</span> <a href="subset_1.html#K4">\/</a> <font color="Maroon">X</font> is <a href="compts_1.html#V6">compact</a>
 <b>by </b><i>, , <a class="ref" href="compts_1.html#T19">COMPTS_1:19</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E5:22"/>
<font color="Maroon">S<sub>1</sub></font>[<font color="Maroon">F</font>]
 
<b>from </b><i><a class="ref" href="finset_1.html#S2">FINSET_1:sch 2</a>(, , );<br/></i>
<b>hence </b><a NAME="E6:22"/>
 <a href="setfam_1.html#K5">union</a> <font color="Maroon">F</font> is <a href="compts_1.html#V6">compact</a>
 ;<br/>


</div>
