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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E9">Th4</font></span>: <a NAME="T4"><span class="comment"><font color="firebrick">:: CLASSES3:4</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">X</font>, <font color="Olive" title="b2">Y</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>  holds <br/> ( <font color="Olive" title="b2">Y</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a>  <a href="classes3.html#K2" title="CLASSES3:func.2">Rrank</a> <font color="Olive" title="b1">X</font> iff  ex <font color="Olive" title="b3">Z</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>  st <br/>( <font color="Olive" title="b3">Z</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Olive" title="b1">X</font> &amp; <font color="Olive" title="b2">Y</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a>  <a href="setfam_1.html#K9" title="SETFAM_1:func.9">bool</a> <span class="p1">(<span class="default"><a href="classes3.html#K2" title="CLASSES3:func.2">Rrank</a> <font color="Olive" title="b3">Z</font></span>)</span> ) )</div></div>
