<?xml version="1.0"?>
<div><span class="kw">theorem </span><a NAME="T37"><span class="comment"><font color="firebrick">:: CLASSES5:37</font></span><br/></a><div class="add">(  <a href="tarski.html#K3" title="TARSKI:func.3">union</a> <span class="p1"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><a href="numbers.html#NK1" title="NUMBERS:NK.1">NAT</a></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span> is  <a href="classes2.html#K13" title="CLASSES2:func.13">FinSETS</a>  <a href="classes5.html#V3" title="CLASSES5:attr.3">-Class</a>  &amp;  not <span class="p1"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><a href="numbers.html#NK1" title="NUMBERS:NK.1">NAT</a></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span> is  <a href="classes2.html#K13" title="CLASSES2:func.13">FinSETS</a>  <a href="classes5.html#V3" title="CLASSES5:attr.3">-Class</a>  &amp;  not <span class="p1"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><a href="numbers.html#NK1" title="NUMBERS:NK.1">NAT</a></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span> is  <a href="classes2.html#K13" title="CLASSES2:func.13">FinSETS</a>  <a href="classes5.html#V2" title="CLASSES5:attr.2">-set</a>  ) <span class="kw">by</span> <span class="lab"><a class="ref" href="classes5.html#T17" target="_self" onmouseover="rs('classes5/T17')" onmouseout="rh()">Th17</a></span>;<br/></div></div>
