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

<b>let </b><font color="Maroon" title="c1">R</font> be   <a href="relat_1.html#NM1" title="RELAT_1:NM.1">Relation</a>;<br/>

<b>thus </b><a NAME="E1:39"/>
( <span class="p1">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p2">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p3">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span> <a href="relat_1.html#K5" title="RELAT_1:func.5">*</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">R</font> <a href="subset_1.html#K6" title="SUBSET_1:func.6">\</a> <span class="p2">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p3">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p4">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  implies ( <font color="Maroon" title="c1">R</font> <a href="relat_1.html#K7" title="RELAT_1:func.7">|</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> &amp; <font color="Maroon" title="c1">R</font> <a href="relat_1.html#K7" title="RELAT_1:func.7">|</a> <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> ) )
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="39_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:39_1"/><i><font color="Green" title="E19">A1</font></i>: 
<span class="p1">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p2">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p3">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span> <a href="relat_1.html#K5" title="RELAT_1:func.5">*</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">R</font> <a href="subset_1.html#K6" title="SUBSET_1:func.6">\</a> <span class="p2">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p3">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p4">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 ;<br/>

<a NAME="E2:39_1"/>
 <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c1">R</font>
 
<b>by </b><i><a class="ref" href="sysrel.html#T53" target="_self" title="SYSREL:th.53">Th53</a></i>;<br/>
<a NAME="E3:39_1"/><b>then </b>
<font color="Maroon" title="c1">R</font> <a href="relat_1.html#K7" title="RELAT_1:func.7">|</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span>
 
<b>by </b><i><a class="txt" href="sysrel.html#E1:39_1"><i><font color="Green" title="E19">A1</font></i></a>, <a class="ref" href="sysrel.html#T54" target="_self" title="SYSREL:th.54">Th54</a></i>;<br/>
<b>hence </b><a NAME="E4:39_1"/>
( <font color="Maroon" title="c1">R</font> <a href="relat_1.html#K7" title="RELAT_1:func.7">|</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> &amp; <font color="Maroon" title="c1">R</font> <a href="relat_1.html#K7" title="RELAT_1:func.7">|</a> <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> )
 <b>by </b><i><a class="ref" href="sysrel.html#T45" target="_self" title="SYSREL:th.45">Th45</a></i>;<br/>


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

<b>thus </b><a NAME="E2:39"/>
( <span class="p1">(<span class="default"><font color="Maroon" title="c1">R</font> <a href="subset_1.html#K6" title="SUBSET_1:func.6">\</a> <span class="p2">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p3">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p4">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span></span>)</span> <a href="relat_1.html#K5" title="RELAT_1:func.5">*</a> <span class="p1">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p2">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p3">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  implies ( <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="relat_1.html#K8" title="RELAT_1:func.8">|</a> <font color="Maroon" title="c1">R</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> &amp; <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="relat_1.html#K8" title="RELAT_1:func.8">|</a> <font color="Maroon" title="c1">R</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> ) )
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="39_2"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:39_2"/><i><font color="Green" title="E19">A2</font></i>: 
<span class="p1">(<span class="default"><font color="Maroon" title="c1">R</font> <a href="subset_1.html#K6" title="SUBSET_1:func.6">\</a> <span class="p2">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p3">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p4">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span></span>)</span> <a href="relat_1.html#K5" title="RELAT_1:func.5">*</a> <span class="p1">(<span class="default"><a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p2">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p3">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 ;<br/>

<a NAME="E2:39_2"/>
 <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c1">R</font>
 
<b>by </b><i><a class="ref" href="sysrel.html#T53" target="_self" title="SYSREL:th.53">Th53</a></i>;<br/>
<a NAME="E3:39_2"/><b>then </b>
<span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="relat_1.html#K8" title="RELAT_1:func.8">|</a> <font color="Maroon" title="c1">R</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span>
 
<b>by </b><i><a class="txt" href="sysrel.html#E1:39_2"><i><font color="Green" title="E19">A2</font></i></a>, <a class="ref" href="sysrel.html#T54" target="_self" title="SYSREL:th.54">Th54</a></i>;<br/>
<a NAME="E4:39_2"/><b>then </b>
<span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="relat_1.html#K8" title="RELAT_1:func.8">|</a> <font color="Maroon" title="c1">R</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="sysrel.html#T45" target="_self" title="SYSREL:th.45">Th45</a></i>;<br/>
<b>hence </b><a NAME="E5:39_2"/>
( <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="relat_1.html#K8" title="RELAT_1:func.8">|</a> <font color="Maroon" title="c1">R</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> &amp; <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> <a href="relat_1.html#K8" title="RELAT_1:func.8">|</a> <font color="Maroon" title="c1">R</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="relat_1.html#K6" title="RELAT_1:func.6">id</a> <span class="p1">(<span class="default"><a href="relat_1.html#K2" title="RELAT_1:func.2">rng</a> <span class="p2">(<span class="default"><a href="sysrel.html#K1" title="SYSREL:func.1">CL</a> <font color="Maroon" title="c1">R</font></span>)</span></span>)</span> )
 <b>by </b><i><a class="ref" href="sysrel.html#T45" target="_self" title="SYSREL:th.45">Th45</a></i>;<br/>


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


</div>
