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<div>:: <span class="kw">deftheorem </span><span class="lab"><font color="Green" title="E37">Def28</font></span>   defines <a href="proofs_1.html#V18" title="PROOFS_1:attr.18">-closed</a> <a onclick="hs(this)" href="javascript:()">PROOFS_1:def 31 : <br/></a><span> for <font color="Olive" title="b1">R</font> being   <a href="proofs_1.html#NM2" title="PROOFS_1:NM.2">Rule</a><br/>  for <font color="Olive" title="b2">X</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>  holds <br/> ( <font color="Olive" title="b2">X</font> is <font color="Olive" title="b1">R</font> <a href="proofs_1.html#V18" title="PROOFS_1:attr.18">-closed</a>  iff  for <font color="Olive" title="b3">Y</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b4">a</font> being    <a href="hidden.html#M1" title="HIDDEN:mode.1">object</a>   st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b3">Y</font>,<font color="Olive" title="b4">a</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> <font color="Olive" title="b1">R</font> &amp; <font color="Olive" title="b3">Y</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Olive" title="b2">X</font> holds <br/><font color="Olive" title="b4">a</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> <font color="Olive" title="b2">X</font> );<br/></span></div>
