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

<b>let </b><font color="Maroon">AP</font> be   <a href="diraf.html#NM2">AffinPlane</a>;<br/><b>let </b><font color="Maroon">a</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">AP</font>;<br/><b>let </b><font color="Maroon">b</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">AP</font>;<br/><b>let </b><font color="Maroon">c</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">AP</font>;<br/><b>let </b><font color="Maroon">d</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">AP</font>;<br/>









<b>assume </b><a NAME="E1:71"/>
not <font color="Maroon">a</font>,<font color="Maroon">b</font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c</font>,<font color="Maroon">d</font>
 ;<br/>

<b>then consider </b><font color="Maroon">p</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">AP</font><b> such that </b><br/><a NAME="E3:71"/><i><font color="Green">E27</font></i>: 
( <font color="Maroon">a</font>,<font color="Maroon">b</font> <a href="analoaf.html#R2">//</a> <font color="Maroon">a</font>,<font color="Maroon">p</font> &amp; <font color="Maroon">c</font>,<font color="Maroon">d</font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c</font>,<font color="Maroon">p</font> )
 <b>by </b><i><a class="ref" href="diraf.html#T54">DIRAF:54</a></i>;<br/>
<a NAME="E4:71"/>
(  <a href="aff_1.html#R1" target="_self">LIN</a> <font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">p</font> &amp;  <a href="aff_1.html#R1" target="_self">LIN</a> <font color="Maroon">c</font>,<font color="Maroon">d</font>,<font color="Maroon">p</font> )
 
<b>by </b><i>, </i>;<br/>
<b>hence </b><a NAME="E5:71"/>
 ex <font color="Olive">p</font> being  <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">AP</font> st <br/>(  <a href="aff_1.html#R1" target="_self">LIN</a> <font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Olive">p</font> &amp;  <a href="aff_1.html#R1" target="_self">LIN</a> <font color="Maroon">c</font>,<font color="Maroon">d</font>,<font color="Olive">p</font> )
 ;<br/>


</div>
