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

<b>let </b><font color="Maroon">SAS</font> be   <a href="semi_af1.html#NM1">Semi_Affine_Space</a>;<br/><b>let </b><font color="Maroon">o</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">SAS</font>;<br/><b>let </b><font color="Maroon">b</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">SAS</font>;<br/><b>let </b><font color="Maroon">d</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">SAS</font>;<br/><b>let </b><font color="Maroon">a</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">SAS</font>;<br/><b>let </b><font color="Maroon">c</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">SAS</font>;<br/>











<b>assume </b><a NAME="E1:103"/>
( ( <font color="Maroon">o</font> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font> or <font color="Maroon">o</font> <a href="hidden.html#R1">=</a> <font color="Maroon">d</font> ) &amp;  <a href="semi_af1.html#R4" target="_self">trap</a> <font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font>,<font color="Maroon">o</font> )
 ;<br/>

<a NAME="E2:103"/><b>then </b>
( ( <font color="Maroon">o</font> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font> &amp;  <a href="semi_af1.html#R4" target="_self">trap</a> <font color="Maroon">c</font>,<font color="Maroon">d</font>,<font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">o</font> ) or ( <font color="Maroon">o</font> <a href="hidden.html#R1">=</a> <font color="Maroon">d</font> &amp;  <a href="semi_af1.html#R4" target="_self">trap</a> <font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font>,<font color="Maroon">o</font> ) )
 
<b>by </b><i><a class="ref" href="semi_af1.html#T61" target="_self">Th61</a></i>;<br/>
<b>hence </b><a NAME="E3:103"/>
( <font color="Maroon">o</font> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font> &amp; <font color="Maroon">o</font> <a href="hidden.html#R1">=</a> <font color="Maroon">d</font> )
 <b>by </b><i><a class="ref" href="semi_af1.html#T62" target="_self">Th62</a></i>;<br/>


</div>
