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

<b>let </b><font color="Maroon">f</font> be   <a href="funct_1.html#NM1">Function</a>;<br/><b>let </b><font color="Maroon">A</font> be    <a href="hidden.html#M1">set</a> ;<br/>



<b>assume </b><a NAME="E1:38"/>
( <font color="Maroon">f</font> is <a href="funct_1.html#V2">one-to-one</a> &amp; <font color="Maroon">A</font> <a href="tarski.html#R1">c=</a>  <a href="zfmisc_1.html#K1">bool</a> <span class="p1">(<span class="default"><a href="relat_1.html#K1">dom</a> <font color="Maroon">f</font></span>)</span> )
 ;<br/>

<a NAME="E2:38"/><b>then </b>
( <span class="p1">(<span class="default"><a href="funct_3.html#K3" target="_self">"</a> <font color="Maroon">f</font></span>)</span> <a href="relat_1.html#K10">"</a> <font color="Maroon">A</font> <a href="tarski.html#R1">c=</a> <span class="p1">(<span class="default"><a href="funct_3.html#K1" target="_self">.:</a> <font color="Maroon">f</font></span>)</span> <a href="relat_1.html#K9">.:</a> <font color="Maroon">A</font> &amp; <span class="p1">(<span class="default"><a href="funct_3.html#K1" target="_self">.:</a> <font color="Maroon">f</font></span>)</span> <a href="relat_1.html#K9">.:</a> <font color="Maroon">A</font> <a href="tarski.html#R1">c=</a> <span class="p1">(<span class="default"><a href="funct_3.html#K3" target="_self">"</a> <font color="Maroon">f</font></span>)</span> <a href="relat_1.html#K10">"</a> <font color="Maroon">A</font> )
 
<b>by </b><i>, </i>;<br/>
<b>hence </b><a NAME="E3:38"/>
<span class="p1">(<span class="default"><a href="funct_3.html#K3" target="_self">"</a> <font color="Maroon">f</font></span>)</span> <a href="relat_1.html#K10">"</a> <font color="Maroon">A</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="funct_3.html#K1" target="_self">.:</a> <font color="Maroon">f</font></span>)</span> <a href="relat_1.html#K9">.:</a> <font color="Maroon">A</font>
 <b>by </b><i><a class="ref" href="xboole_0.html#D10">XBOOLE_0:def 10</a></i>;<br/>


</div>
