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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E15">Th15</font></span>: <a NAME="T15"><span class="comment"><font color="firebrick">:: CARD_FIL:15</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="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b2">S</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>  holds <br/> ( <font color="Olive" title="b2">S</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a>  <a href="card_fil.html#K3" title="CARD_FIL:func.3">Filters</a> <font color="Olive" title="b1">X</font> iff <font color="Olive" title="b2">S</font> is    <a href="card_fil.html#M1" title="CARD_FIL:mode.1">Filter</a> of <font color="Olive" title="b1">X</font> )</div></div>
