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

<b>let </b><font color="Maroon" title="c1">FdSp</font> be   <a href="parsp_2.html#NM1" title="PARSP_2:NM.1">FanodesSp</a>;<br/><b>let </b><font color="Maroon" title="c2">a</font>, <font color="Maroon" title="c3">b</font>, <font color="Maroon" title="c4">c</font>, <font color="Maroon" title="c5">d</font> be   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <font color="Maroon" title="c1">FdSp</font>;<br/>









<b>assume </b><a NAME="E1:52"/>
 <a href="parsp_2.html#R2" title="PARSP_2:pred.2">parallelogram</a> <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">d</font>
 ;<br/>

<a NAME="E2:52"/><b>then </b>
not <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c5">d</font> <a href="parsp_1.html#R1" title="PARSP_1:pred.1">'||'</a> <font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c4">c</font>
 
<b>by </b><i><a class="ref" href="parsp_2.html#T44" target="_self" title="PARSP_2:th.44">Th44</a></i>;<br/>
<b>hence </b><a NAME="E3:52"/>
not  <a href="parsp_2.html#R2" title="PARSP_2:pred.2">parallelogram</a> <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c5">d</font>,<font color="Maroon" title="c4">c</font>
 <b>by </b><i><a class="ref" href="parsp_2.html#D3" target="_self" title="PARSP_2:def.3">Def3</a></i>;<br/>


</div>
