<?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>let </b><font color="Maroon">C</font> be   <a href="incsp_1.html#NM1">POINT</a> of <font color="Maroon">S</font>;<br/>







<b>assume </b><a NAME="E1:55"/><i><font color="Green">E23</font></i>: 
not <span class="p1"><a href="domain_1.html#K8">{</a><span class="default"><font color="Maroon">A</font>,<font color="Maroon">B</font>,<font color="Maroon">C</font></span><a href="domain_1.html#K8">}</a></span> <a href="incsp_1.html#NR6" target="_self">is_collinear</a> 
 ;<br/>

<a NAME="E2:55"/><b>then </b><i><font color="Green">E24</font></i>: 
not <span class="p1"><a href="domain_1.html#K8">{</a><span class="default"><font color="Maroon">C</font>,<font color="Maroon">B</font>,<font color="Maroon">A</font></span><a href="domain_1.html#K8">}</a></span> <a href="incsp_1.html#NR6" target="_self">is_collinear</a> 
 
<b>by </b><i><a class="ref" href="enumset1.html#T102">ENUMSET1:102</a></i>;<br/>
<b>thus </b> <a href="incsp_1.html#K2" target="_self">Plane</a> <font color="Maroon">A</font>,<font color="Maroon">B</font>,<font color="Maroon">C</font> = 
 <a href="incsp_1.html#K2" target="_self">Plane</a> <font color="Maroon">C</font>,<font color="Maroon">A</font>,<font color="Maroon">B</font>
<b>by </b><i><a class="ref" href="incsp_1.html#D8" target="_self">Def8</a>, </i>
<br/>.= 
 <a href="incsp_1.html#K2" target="_self">Plane</a> <font color="Maroon">C</font>,<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></i>
;<br/>


</div>
