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

<b>consider </b><font color="Maroon">d</font> being    <a href="subset_1.html#M1">Element</a> of <font color="Maroon">D</font>;<br/>
<b>take </b>
<span class="p1"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span>
;<br/>

<b>thus </b><a NAME="E2:99_2_1"/>
<span class="p1"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span> is <a href="finseq_6.html#V1" target="_self">circular</a>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="99_2_1_1"><b>proof </b></a><div class="add">

<a NAME="E1:99_2_1_1"/>
 <a href="finseq_1.html#K3">len</a> <span class="p1"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span> <a href="hidden.html#R1">=</a> 2
 
<b>by </b><i><a class="ref" href="finseq_1.html#T61">FINSEQ_1:61</a></i>;<br/>
<b>hence </b><span class="p1"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span> <a href="finseq_4.html#K4">/.</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <span class="p2"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span></span>)</span> = 
<font color="Maroon">d</font>
<b>by </b><i><a class="ref" href="finseq_4.html#T26">FINSEQ_4:26</a></i>
<br/>.= 
<span class="p1"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span> <a href="finseq_4.html#K4">/.</a> 1
<b>by </b><i><a class="ref" href="finseq_4.html#T26">FINSEQ_4:26</a></i>
;<br/> <i><font color="Red">:: according to </font></i><a class="ref" href="finseq_6.html#D1" target="_self">FINSEQ_6:def 1</a><br/>


</div><b>end;</b></div>

<b>thus </b><a NAME="E3:99_2_1"/>
( not <span class="p1"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span> is <a href="xboole_0.html#V1">empty</a> &amp; not <span class="p1"><a href="finseq_4.html#K2">&lt;*</a><span class="default"><font color="Maroon">d</font>,<font color="Maroon">d</font></span><a href="finseq_4.html#K2">*&gt;</a></span> is <a href="realset1.html#V1">trivial</a> )
 ;<br/>


</div>
