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<div><span class="kw">theorem </span><a NAME="T27"><span class="comment"><font color="firebrick">:: CLASSES5:27</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">U</font> being   <a href="classes2.html#NM1" title="CLASSES2:NM.1">Universe</a><br/>  for <font color="Olive" title="b2">x</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>   st <font color="Olive" title="b2">x</font> is <font color="Olive" title="b1">U</font> <a href="classes5.html#V3" title="CLASSES5:attr.3">-Class</a>  holds <br/> not <font color="Olive" title="b2">x</font> is  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>  <span class="kw">by</span> <span class="lab"><a class="ref" href="classes4.html#T13" onmouseover="rs('classes4/T13')" onmouseout="rh()">CLASSES4:13</a></span>;<br/></div></div>
