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

<b>let </b><font color="Maroon">Y</font> be  non <a href="xboole_0.html#V1">empty</a>  <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">G</font> be   <a href="subset_1.html#NM2">Subset</a> of <span class="p1">(<span class="default"><a href="bvfunc_2.html#K1">PARTITIONS</a> <font color="Maroon">Y</font></span>)</span>;<br/><b>let </b><font color="Maroon">A</font> be    <a href="eqrel_1.html#M1">a_partition</a> of <font color="Maroon">Y</font>;<br/><b>let </b><font color="Maroon">B</font> be    <a href="eqrel_1.html#M1">a_partition</a> of <font color="Maroon">Y</font>;<br/><b>let </b><font color="Maroon">C</font> be    <a href="eqrel_1.html#M1">a_partition</a> of <font color="Maroon">Y</font>;<br/><b>let </b><font color="Maroon">D</font> be    <a href="eqrel_1.html#M1">a_partition</a> of <font color="Maroon">Y</font>;<br/><b>let </b><font color="Maroon">z</font> be    <a href="subset_1.html#M1">Element</a> of <font color="Maroon">Y</font>, <font color="Maroon">u</font> be    <a href="subset_1.html#M1">Element</a> of <font color="Maroon">Y</font>;<br/><b>let </b><font color="Maroon">h</font> be   <a href="funct_1.html#NM1">Function</a>;<br/>















<b>assume </b><a NAME="E1:18"/><i><font color="Green">E20</font></i>: 
( <font color="Maroon">G</font> is <a href="bvfunc_2.html#V2">independent</a> &amp; <font color="Maroon">G</font> <a href="hidden.html#R1">=</a> <span class="p1"><a href="enumset1.html#K2">{</a><span class="default"><font color="Maroon">A</font>,<font color="Maroon">B</font>,<font color="Maroon">C</font>,<font color="Maroon">D</font></span><a href="enumset1.html#K2">}</a></span> &amp; <font color="Maroon">A</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">B</font> &amp; <font color="Maroon">A</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">C</font> &amp; <font color="Maroon">A</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">D</font> &amp; <font color="Maroon">B</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">C</font> &amp; <font color="Maroon">B</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">D</font> &amp; <font color="Maroon">C</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">D</font> )
 ;<br/>

<b>set </b><font color="Maroon">h</font> = <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p1">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p2">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span>;<br/>
<a NAME="E2:18"/><i><font color="Green">E22</font></i>: 
 <a href="relat_1.html#K1">dom</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">G</font>
 
<b>by </b><i>, </i>;<br/>
<a NAME="E3:18"/><i><font color="Green">E23</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">A</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font>
 
<b>by </b><i><a class="ref" href="yellow14.html#T3">YELLOW14:3</a></i>;<br/>
<a NAME="E4:18"/><i><font color="Green">E24</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">B</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font>
 
<b>by </b><i>, </i>;<br/>
<a NAME="E5:18"/><i><font color="Green">E25</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">C</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font>
 
<b>by </b><i>, </i>;<br/>
<a NAME="E6:18"/><i><font color="Green">E26</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">D</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font>
 
<b>by </b><i>, </i>;<br/>
<a NAME="E7:18"/><i><font color="Green">E27</font></i>: 
for <font color="Olive">d</font> being   <a href="hidden.html#M1">set</a>   st <font color="Olive">d</font> <a href="hidden.html#R2">in</a> <font color="Maroon">G</font> holds <br/><span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Olive">d</font> <a href="hidden.html#R2">in</a> <font color="Olive">d</font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="18_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">d</font> be    <a href="hidden.html#M1">set</a> ;<br/>

<b>assume </b><a NAME="E1:18_1"/><i><font color="Green">E28</font></i>: 
<font color="Maroon">d</font> <a href="hidden.html#R2">in</a> <font color="Maroon">G</font>
 ;<br/>

<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_1_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:18_1_1"/>
( <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">A</font> or <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">B</font> or <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">C</font> or <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">D</font> )
 </span><b>by </b><i>, <a class="txt" href="bvfunc14.html#E1:18"><i><font color="Green">E20</font></i></a>, <a class="ref" href="enumset1.html#D2">ENUMSET1:def 2</a></i>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_1_1_1"><b>suppose </b></a><a NAME="E1:18_1_1_1"/><i><font color="Green">E29</font></i>: 
<font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">A</font>
 ;<br/><div class="add"><a NAME="E2:18_1_1_1"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">A</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font>
 <b>by </b><i><a class="ref" href="yellow14.html#T3">YELLOW14:3</a></i>;<br/><b>hence </b><a NAME="E3:18_1_1_1"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">d</font> <a href="hidden.html#R2">in</a> <font color="Maroon">d</font>
 <b>by </b><i/>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_1_1_2"><b>suppose </b></a><a NAME="E1:18_1_1_2"/><i><font color="Green">E30</font></i>: 
<font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">B</font>
 ;<br/><div class="add"><a NAME="E2:18_1_1_2"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">B</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font>
 <b>by </b><i>, </i>;<br/><b>hence </b><a NAME="E3:18_1_1_2"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">d</font> <a href="hidden.html#R2">in</a> <font color="Maroon">d</font>
 <b>by </b><i/>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_1_1_3"><b>suppose </b></a><a NAME="E1:18_1_1_3"/><i><font color="Green">E31</font></i>: 
<font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">C</font>
 ;<br/><div class="add"><a NAME="E2:18_1_1_3"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">C</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font>
 <b>by </b><i>, </i>;<br/><b>hence </b><a NAME="E3:18_1_1_3"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">d</font> <a href="hidden.html#R2">in</a> <font color="Maroon">d</font>
 <b>by </b><i/>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_1_1_4"><b>suppose </b></a><a NAME="E1:18_1_1_4"/><i><font color="Green">E32</font></i>: 
<font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">D</font>
 ;<br/><div class="add"><a NAME="E2:18_1_1_4"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">D</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font>
 <b>by </b><i>, </i>;<br/><b>hence </b><a NAME="E3:18_1_1_4"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">d</font> <a href="hidden.html#R2">in</a> <font color="Maroon">d</font>
 <b>by </b><i/>;<br/></div><b>end;</b></div></div><b>end;</b></div>

</div><b>end;</b></div>
<a NAME="E8:18"/>
<font color="Maroon">A</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K1">dom</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i>, , <a class="ref" href="enumset1.html#D2">ENUMSET1:def 2</a></i>;<br/>
<a NAME="E9:18"/><b>then </b><i><font color="Green">E35</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">A</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="funct_1.html#D5">FUNCT_1:def 5</a></i>;<br/>
<a NAME="E10:18"/>
<font color="Maroon">B</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K1">dom</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i>, , <a class="ref" href="enumset1.html#D2">ENUMSET1:def 2</a></i>;<br/>
<a NAME="E11:18"/><b>then </b><i><font color="Green">E36</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">B</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="funct_1.html#D5">FUNCT_1:def 5</a></i>;<br/>
<a NAME="E12:18"/>
<font color="Maroon">C</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K1">dom</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i>, , <a class="ref" href="enumset1.html#D2">ENUMSET1:def 2</a></i>;<br/>
<a NAME="E13:18"/><b>then </b><i><font color="Green">E37</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">C</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="funct_1.html#D5">FUNCT_1:def 5</a></i>;<br/>
<a NAME="E14:18"/>
<font color="Maroon">D</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K1">dom</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i>, , <a class="ref" href="enumset1.html#D2">ENUMSET1:def 2</a></i>;<br/>
<a NAME="E15:18"/><b>then </b><i><font color="Green">E38</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">D</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="funct_1.html#D5">FUNCT_1:def 5</a></i>;<br/>
<a NAME="E16:18"/><i><font color="Green">E39</font></i>: 
 <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="enumset1.html#K2">{</a><span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><span class="p5">(<span class="default"><span class="p0">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p0">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p5">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p0">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">A</font></span>)</span>,<span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><span class="p5">(<span class="default"><span class="p0">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p0">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p5">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p0">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">B</font></span>)</span>,<span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><span class="p5">(<span class="default"><span class="p0">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p0">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p5">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p0">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">C</font></span>)</span>,<span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><span class="p5">(<span class="default"><span class="p0">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p0">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p5">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p0">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">D</font></span>)</span></span><a href="enumset1.html#K2">}</a></span>
 
<b>by </b><i>, </i>;<br/>
<a NAME="E17:18"/>
 <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="tarski.html#R1">c=</a>  <a href="zfmisc_1.html#K1">bool</a> <font color="Maroon">Y</font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="18_2"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">t</font> be    <a href="hidden.html#M1">set</a> ; <i><font color="Red">:: according to </font></i><a class="ref" href="tarski.html#D3">TARSKI:def 3</a><br/>

<b>assume </b><a NAME="E1:18_2"/><i><font color="Green">E47</font></i>: 
<font color="Maroon">t</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span>
 ;<br/>

<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_2_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:18_2_1"/>
( <font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">A</font> or <font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">B</font> or <font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">C</font> or <font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">D</font> )
 </span><b>by </b><i><a class="txt" href="bvfunc14.html#E4:18"><i><font color="Green">E24</font></i></a>, <a class="txt" href="bvfunc14.html#E5:18"><i><font color="Green">E25</font></i></a>, <a class="ref" href="enumset1.html#D2">ENUMSET1:def 2</a></i>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_2_1_1"><b>suppose </b></a><a NAME="E1:18_2_1_1"/>
<font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">A</font>
 ;<br/><div class="add"><a NAME="E2:18_2_1_1"/><b>then </b>
<font color="Maroon">t</font> <a href="hidden.html#R1">=</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font>
 <b>by </b><i><a class="ref" href="yellow14.html#T3">YELLOW14:3</a></i>;<br/><b>hence </b><a NAME="E3:18_2_1_1"/>
<font color="Maroon">t</font> <a href="hidden.html#R2">in</a>  <a href="zfmisc_1.html#K1">bool</a> <font color="Maroon">Y</font>
 ;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_2_1_2"><b>suppose </b></a><a NAME="E1:18_2_1_2"/>
<font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">B</font>
 ;<br/><div class="add"><b>hence </b><a NAME="E2:18_2_1_2"/>
<font color="Maroon">t</font> <a href="hidden.html#R2">in</a>  <a href="zfmisc_1.html#K1">bool</a> <font color="Maroon">Y</font>
 <b>by </b><i><a class="ref" href="bvfunc14.html#T1" target="_self">Th1</a></i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_2_1_3"><b>suppose </b></a><a NAME="E1:18_2_1_3"/>
<font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">C</font>
 ;<br/><div class="add"><b>hence </b><a NAME="E2:18_2_1_3"/>
<font color="Maroon">t</font> <a href="hidden.html#R2">in</a>  <a href="zfmisc_1.html#K1">bool</a> <font color="Maroon">Y</font>
 <b>by </b><i/>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="18_2_1_4"><b>suppose </b></a><a NAME="E1:18_2_1_4"/>
<font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">D</font>
 ;<br/><div class="add"><b>hence </b><a NAME="E2:18_2_1_4"/>
<font color="Maroon">t</font> <a href="hidden.html#R2">in</a>  <a href="zfmisc_1.html#K1">bool</a> <font color="Maroon">Y</font>
 <b>by </b><i/>;<br/></div><b>end;</b></div></div><b>end;</b></div>

</div><b>end;</b></div>
<b>then reconsider </b><font color="Maroon">FF</font> =  <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> as   <a href="setfam_1.html#NM1">Subset-Family</a> of <font color="Maroon">Y</font> ;<br/>
<a NAME="E19:18"/>
 <a href="setfam_1.html#K8">Intersect</a> <font color="Maroon">FF</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 
<b>by </b><i>, , , <a class="ref" href="bvfunc_2.html#D5">BVFUNC_2:def 5</a></i>;<br/>
<b>then consider </b><font color="Maroon">m</font> being    <a href="hidden.html#M1">set</a> <b> such that </b><br/><a NAME="E21:18"/><i><font color="Green">E48</font></i>: 
<font color="Maroon">m</font> <a href="hidden.html#R2">in</a>  <a href="setfam_1.html#K8">Intersect</a> <font color="Maroon">FF</font>
 <b>by </b><i><a class="ref" href="xboole_0.html#D1">XBOOLE_0:def 1</a></i>;<br/>
<a NAME="E22:18"/>
<font color="Maroon">m</font> <a href="hidden.html#R2">in</a>  <a href="setfam_1.html#K6">meet</a> <font color="Maroon">FF</font>
 
<b>by </b><i><a class="txt" href="bvfunc14.html#E1:18"><i><font color="Green">E20</font></i></a>, <a class="txt" href="bvfunc14.html#E5:18"><i><font color="Green">E25</font></i></a>, <a class="ref" href="setfam_1.html#D10">SETFAM_1:def 10</a></i>;<br/>
<a NAME="E23:18"/><b>then </b><i><font color="Green">E49</font></i>: 
( <font color="Maroon">m</font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">A</font> &amp; <font color="Maroon">m</font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">B</font> &amp; <font color="Maroon">m</font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">C</font> &amp; <font color="Maroon">m</font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><span class="p4">(<span class="default"><font color="Maroon">B</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p4">(<span class="default"><font color="Maroon">C</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p5">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p3">(<span class="default"><font color="Maroon">D</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p4">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span></span>)</span> <a href="funct_4.html#K1">+*</a> <span class="p2">(<span class="default"><font color="Maroon">A</font> <a href="cqc_lang.html#K3">.--&gt;</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">D</font> )
 
<b>by </b><i><a class="txt" href="bvfunc14.html#E1:18"><i><font color="Green">E20</font></i></a>, , <a class="txt" href="bvfunc14.html#E2:18"><i><font color="Green">E22</font></i></a>, <a class="txt" href="bvfunc14.html#E3:18"><i><font color="Green">E23</font></i></a>, <a class="ref" href="setfam_1.html#D1">SETFAM_1:def 1</a></i>;<br/>
<a NAME="E24:18"/><i><font color="Green">E50</font></i>: 
 <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">B</font> <a href="partit1.html#K2">'/\'</a> <font color="Maroon">C</font></span>)</span> <a href="partit1.html#K2">'/\'</a> <font color="Maroon">D</font></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<span class="p2">(<span class="default"><font color="Maroon">B</font> <a href="partit1.html#K2">'/\'</a> <font color="Maroon">C</font></span>)</span></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span>
 
<b>by </b><i/>;<br/>
<a NAME="E25:18"/>
<font color="Maroon">m</font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span>
 
<b>by </b><i><a class="ref" href="bvfunc14.html#T1" target="_self">Th1</a>, , <a class="txt" href="bvfunc14.html#E6:18"><i><font color="Green">E26</font></i></a>, <a class="ref" href="xboole_0.html#D3">XBOOLE_0:def 3</a></i>;<br/>
<a NAME="E26:18"/><b>then </b>
<font color="Maroon">m</font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p2">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span>
 
<b>by </b><i>, <a class="txt" href="bvfunc14.html#E6:18"><i><font color="Green">E26</font></i></a>, <a class="ref" href="xboole_0.html#D3">XBOOLE_0:def 3</a></i>;<br/>
<a NAME="E27:18"/><b>then </b>
<font color="Maroon">m</font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p3">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p2">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font></span>)</span>
 
<b>by </b><i>, <a class="txt" href="bvfunc14.html#E6:18"><i><font color="Green">E26</font></i></a>, <a class="ref" href="xboole_0.html#D3">XBOOLE_0:def 3</a></i>;<br/>
<a NAME="E28:18"/><b>then </b>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">B</font></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p2">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">C</font></span>)</span></span>)</span> <a href="subset_1.html#K9">/\</a> <span class="p1">(<span class="default"><a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<font color="Maroon">D</font></span>)</span> <a href="xboole_0.html#NR5" target="_self">meets</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font>
 
<b>by </b><i><a class="ref" href="xboole_0.html#T4">XBOOLE_0:4</a></i>;<br/>
<b>hence </b><a NAME="E29:18"/>
 <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">u</font>,<span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">B</font> <a href="partit1.html#K2">'/\'</a> <font color="Maroon">C</font></span>)</span> <a href="partit1.html#K2">'/\'</a> <font color="Maroon">D</font></span>)</span> <a href="xboole_0.html#NR5" target="_self">meets</a>  <a href="bvfunc_1.html#K20">EqClass</a> <font color="Maroon">z</font>,<font color="Maroon">A</font>
 <b>by </b><i><a class="txt" href="bvfunc14.html#E7:18"><i><font color="Green">E27</font></i></a>, </i>;<br/>


</div>
