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<div><span class="kw">theorem </span><a NAME="T10"><span class="comment"><font color="firebrick">:: MEMBERED:10</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">X</font> being   non  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>   <a href="membered.html#V4" title="MEMBERED:attr.4">rational-membered</a>   <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>   ex <font color="Olive" title="b2">w</font> being   <a href="rat_1.html#NM1" title="RAT_1:NM.1">Rational</a> st <font color="Olive" title="b2">w</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> <font color="Olive" title="b1">X</font></div></div>
