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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E5">Th4</font></span>: <a NAME="T4"><span class="comment"><font color="firebrick">:: ABIAN:4</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">E</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b2">sE</font> being   <a href="setfam_1.html#NM1" title="SETFAM_1:NM.1">Subset-Family</a> of <font color="Olive" title="b1">E</font> holds <br/> ( <font color="Olive" title="b2">sE</font> is  <a href="abian.html#V3" title="ABIAN:attr.3">covering</a>  iff  <a href="setfam_1.html#K5" title="SETFAM_1:func.5">union</a> <font color="Olive" title="b2">sE</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b1">E</font> )</div></div>
