<?xml version="1.0"?>
<div><span class="kw">theorem </span><a NAME="T21"><span class="comment"><font color="firebrick">:: PRE_CIRC:21</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">f</font>, <font color="Olive" title="b2">g</font> being   <a href="funct_1.html#NM1" title="FUNCT_1:NM.1">Function</a> holds <br/> (  <a href="relat_1.html#NK1" title="RELAT_1:NK.1">dom</a> <font color="Olive" title="b1">f</font>, <a href="relat_1.html#NK1" title="RELAT_1:NK.1">dom</a> <font color="Olive" title="b2">g</font> <a href="tarski.html#R3" title="TARSKI:pred.3">are_equipotent</a>  iff <font color="Olive" title="b1">f</font>,<font color="Olive" title="b2">g</font> <a href="tarski.html#R3" title="TARSKI:pred.3">are_equipotent</a>  )</div></div>
