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

<b>let </b><font color="Maroon">S</font> be   <a href="incsp_1.html#NM4">IncSpace</a>;<br/><b>let </b><font color="Maroon">A</font> be   <a href="incsp_1.html#NM1">POINT</a> of <font color="Maroon">S</font>;<br/><b>let </b><font color="Maroon">B</font> be   <a href="incsp_1.html#NM1">POINT</a> of <font color="Maroon">S</font>;<br/>





<b>assume </b><a NAME="E1:50"/><i><font color="Green">E23</font></i>: 
<font color="Maroon">A</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">B</font>
 ;<br/>

<a NAME="E2:50"/><b>then </b>
( <span class="p1"><a href="domain_1.html#K7">{</a><span class="default"><font color="Maroon">A</font>,<font color="Maroon">B</font></span><a href="domain_1.html#K7">}</a></span> <a href="incsp_1.html#R4" target="_self">on</a>  <a href="incsp_1.html#K1" target="_self">Line</a> <font color="Maroon">A</font>,<font color="Maroon">B</font> &amp; <span class="p1"><a href="domain_1.html#K7">{</a><span class="default"><font color="Maroon">A</font>,<font color="Maroon">B</font></span><a href="domain_1.html#K7">}</a></span> <a href="incsp_1.html#R4" target="_self">on</a>  <a href="incsp_1.html#K1" target="_self">Line</a> <font color="Maroon">B</font>,<font color="Maroon">A</font> )
 
<b>by </b><i><a class="ref" href="incsp_1.html#T17" target="_self">Th17</a></i>;<br/>
<b>hence </b><a NAME="E3:50"/>
 <a href="incsp_1.html#K1" target="_self">Line</a> <font color="Maroon">A</font>,<font color="Maroon">B</font> <a href="hidden.html#R1">=</a>  <a href="incsp_1.html#K1" target="_self">Line</a> <font color="Maroon">B</font>,<font color="Maroon">A</font>
 <b>by </b><i><a class="ref" href="incsp_1.html#T21" target="_self">Th21</a>, <a class="ref" href="incsp_1.html#D5" target="_self">Def5</a></i>;<br/>


</div>
