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<b>take </b><font color="Maroon">f</font> =  <a href="grcat_1.html#K7">id</a> <font color="Maroon">S</font>;<br/>

<b>thus </b><a NAME="E1:18_1_1"/>
<font color="Maroon">f</font> is <a href="pencil_2.html#V1" target="_self">isomorphic</a>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="18_1_1_1"><b>proof </b></a><div class="add">

<a NAME="E1:18_1_1_1"/><i><font color="Green">E32</font></i>: 
<font color="Maroon">f</font> <a href="funct_2.html#R2">=</a>  <a href="partfun1.html#K6">id</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">S</font>
 
<b>by </b><i><a class="ref" href="grcat_1.html#D11">GRCAT_1:def 11</a></i>;<br/>
<b>hence </b><a NAME="E2:18_1_1_1"/>
<font color="Maroon">f</font> is <a href="funct_2.html#V3">bijective</a>
 ; <i><font color="Red">:: according to </font></i><a class="ref" href="pencil_2.html#D4" target="_self">PENCIL_2:def 4</a><br/>

<b>thus </b><a NAME="E3:18_1_1_1"/>
<font color="Maroon">f</font> is <a href="t_0topsp.html#V1">open</a>
 ;<br/>

<b>thus </b><a NAME="E4:18_1_1_1"/>
( <font color="Maroon">f</font> <a href="tops_2.html#NK3" target="_self">"</a>  is <a href="funct_2.html#V3">bijective</a> &amp; <font color="Maroon">f</font> <a href="tops_2.html#NK3" target="_self">"</a>  is <a href="t_0topsp.html#V1">open</a> )
 <b>by </b><i>, <a class="ref" href="topgrp_1.html#T2">TOPGRP_1:2</a></i>;<br/>


</div><b>end;</b></div>


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