<?xml version="1.0"?>
<div><span class="kw">theorem </span><a NAME="T1"><span class="comment"><font color="firebrick">:: NUMERALS:1</font></span><br/></a><div class="add"> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  is    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="ordinal1.html#K4" title="ORDINAL1:func.4">omega</a> </div></div>
