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<div><span class="kw">theorem </span><a NAME="T18"><span class="comment"><font color="firebrick">:: SYSREL:18</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">X</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b2">R</font> being   <a href="relat_1.html#NM1" title="RELAT_1:NM.1">Relation</a>  st  <a href="relat_1.html#K4" title="RELAT_1:func.4">id</a> <font color="Olive" title="b1">X</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Olive" title="b2">R</font> <a href="xboole_0.html#K2" title="XBOOLE_0:func.2">\/</a> <span class="p1">(<span class="default"><font color="Olive" title="b2">R</font> <a href="relat_1.html#K2" title="RELAT_1:func.2">~</a></span>)</span> holds <br/>(  <a href="relat_1.html#K4" title="RELAT_1:func.4">id</a> <font color="Olive" title="b1">X</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Olive" title="b2">R</font> &amp;  <a href="relat_1.html#K4" title="RELAT_1:func.4">id</a> <font color="Olive" title="b1">X</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Olive" title="b2">R</font> <a href="relat_1.html#K2" title="RELAT_1:func.2">~</a>  )</div></div>
