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

<b>let </b><font color="Maroon" title="c4">S</font>, <font color="Maroon" title="c5">T</font> be  non <a href="struct_0.html#V2" title="STRUCT_0:attr.2">empty</a> <a href="pre_topc.html#NM1" title="PRE_TOPC:NM.1">TopSpace</a>;<br/><b>let </b><font color="Maroon" title="c6">s1</font>, <font color="Maroon" title="c7">s2</font> be   <a href="pre_topc.html#NM2" title="PRE_TOPC:NM.2">Point</a> of <font color="Maroon" title="c4">S</font>;<br/><b>let </b><font color="Maroon" title="c8">t1</font>, <font color="Maroon" title="c9">t2</font> be   <a href="pre_topc.html#NM2" title="PRE_TOPC:NM.2">Point</a> of <font color="Maroon" title="c5">T</font>;<br/><b>let </b><font color="Maroon" title="c10">f</font> be   <a href="group_6.html#NM2" title="GROUP_6:NM.2">Homomorphism</a> of <span class="p1">(<span class="default"><a href="topalg_1.html#NK4" title="TOPALG_1:NK.4">pi_1</a> <font color="Maroon" title="c4">S</font>,<font color="Maroon" title="c6">s1</font></span>)</span>,<span class="p1">(<span class="default"><a href="topalg_1.html#NK4" title="TOPALG_1:NK.4">pi_1</a> <font color="Maroon" title="c4">S</font>,<font color="Maroon" title="c7">s2</font></span>)</span>;<br/><b>let </b><font color="Maroon" title="c11">g</font> be   <a href="group_6.html#NM2" title="GROUP_6:NM.2">Homomorphism</a> of <span class="p1">(<span class="default"><a href="topalg_1.html#NK4" title="TOPALG_1:NK.4">pi_1</a> <font color="Maroon" title="c5">T</font>,<font color="Maroon" title="c8">t1</font></span>)</span>,<span class="p1">(<span class="default"><a href="topalg_1.html#NK4" title="TOPALG_1:NK.4">pi_1</a> <font color="Maroon" title="c5">T</font>,<font color="Maroon" title="c9">t2</font></span>)</span>;<br/>















<b>assume </b><b>that </b><br/><a NAME="E1:46"/><i><font color="Green" title="E32">A1</font></i>: 
<font color="Maroon" title="c10">f</font> <a href="group_6.html#NR3" title="GROUP_6:NR.3">is_isomorphism</a> 
 <b>and </b><br/><a NAME="E2:46"/><i><font color="Green" title="E33">A2</font></i>: 
<font color="Maroon" title="c11">g</font> <a href="group_6.html#NR3" title="GROUP_6:NR.3">is_isomorphism</a> 
 ;<br/>

<a NAME="E3:46"/><i><font color="Green" title="E34">A3</font></i>: 
 <a href="topalg_4.html#K13" title="TOPALG_4:func.13">FGPrIso</a> <font color="Maroon" title="c6">s1</font>,<font color="Maroon" title="c8">t1</font> <a href="group_6.html#NR3" title="GROUP_6:NR.3">is_isomorphism</a> 
 
<b>by </b><i><a class="ref" href="topalg_4.html#T29" target="_self" title="TOPALG_4:th.29">Th29</a></i>;<br/>
<a NAME="E4:46"/>
 <a href="topalg_4.html#K2" title="TOPALG_4:func.2">Gr2Iso</a> <font color="Maroon" title="c10">f</font>,<font color="Maroon" title="c11">g</font> <a href="group_6.html#NR3" title="GROUP_6:NR.3">is_isomorphism</a> 
 
<b>by </b><i><a class="txt" href="topalg_4.html#E1:46"><i><font color="Green" title="E32">A1</font></i></a>, <a class="txt" href="topalg_4.html#E2:46"><i><font color="Green" title="E33">A2</font></i></a>, <a class="ref" href="topalg_4.html#T5" target="_self" title="TOPALG_4:th.5">Th5</a></i>;<br/>
<b>hence </b><a NAME="E5:46"/>
<span class="p1">(<span class="default"><a href="topalg_4.html#K2" title="TOPALG_4:func.2">Gr2Iso</a> <font color="Maroon" title="c10">f</font>,<font color="Maroon" title="c11">g</font></span>)</span> <a href="group_6.html#K8" title="GROUP_6:func.8">*</a> <span class="p1">(<span class="default"><a href="topalg_4.html#K13" title="TOPALG_4:func.13">FGPrIso</a> <font color="Maroon" title="c6">s1</font>,<font color="Maroon" title="c8">t1</font></span>)</span> <a href="group_6.html#NR3" title="GROUP_6:NR.3">is_isomorphism</a> 
 <b>by </b><i><a class="txt" href="topalg_4.html#E3:46"><i><font color="Green" title="E34">A3</font></i></a>, <a class="ref" href="group_6.html#T74" title="GROUP_6:th.74">GROUP_6:74</a></i>;<br/>


</div>
