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<div><span class="kw">theorem </span><a NAME="T71"><span class="comment"><font color="firebrick">:: PBOOLE:71</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">I</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b2">X</font>, <font color="Olive" title="b3">Y</font> being   <a href="pboole.html#NM1" title="PBOOLE:NM.1">ManySortedSet</a> of <font color="Olive" title="b1">I</font> holds <br/> ( <font color="Olive" title="b2">X</font> <a href="pboole.html#K3" title="PBOOLE:func.3">(/\)</a> <font color="Olive" title="b3">Y</font> <a href="pboole.html#R6" title="PBOOLE:pred.6">=</a>  <a href="pboole.html#K1" title="PBOOLE:func.1">EmptyMS</a> <font color="Olive" title="b1">I</font> iff <font color="Olive" title="b2">X</font> <a href="pboole.html#K4" title="PBOOLE:func.4">(\)</a> <font color="Olive" title="b3">Y</font> <a href="pboole.html#R6" title="PBOOLE:pred.6">=</a> <font color="Olive" title="b2">X</font> )</div></div>
