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

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

<b>take </b>
 <a href="relat_1.html#K6">id</a> <font color="Maroon">X</font>
;<br/>

<b>thus </b><a NAME="E1:18_1_2"/>
(  <a href="relat_1.html#K6">id</a> <font color="Maroon">X</font> is <a href="funct_1.html#V2">one-to-one</a> &amp;  <a href="relat_1.html#K1">dom</a> <span class="p1">(<span class="default"><a href="relat_1.html#K6">id</a> <font color="Maroon">X</font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">X</font> &amp;  <a href="relat_1.html#K2">rng</a> <span class="p1">(<span class="default"><a href="relat_1.html#K6">id</a> <font color="Maroon">X</font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">X</font> )
 <b>by </b><i><a class="ref" href="funct_1.html#T52">FUNCT_1:52</a>, <a class="ref" href="relat_1.html#T71">RELAT_1:71</a></i>;<br/>


</div>
