<?xml version="1.0"?>
<div><span class="kw">theorem </span><a NAME="T1"><span class="comment"><font color="firebrick">:: PBOOLE:1</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">f</font> being   <a href="funct_1.html#NM1" title="FUNCT_1:NM.1">Function</a>  st <font color="Olive" title="b1">f</font> is  <a href="relat_1.html#V2" title="RELAT_1:attr.2">non-empty</a>  holds <br/> <a href="xtuple_0.html#K10" title="XTUPLE_0:func.10">rng</a> <font color="Olive" title="b1">f</font> is  <a href="setfam_1.html#V1" title="SETFAM_1:attr.1">with_non-empty_elements</a>  ;<br/></div></div>
