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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E4">Th2</font></span>: <a NAME="T2"><span class="comment"><font color="firebrick">:: MATROID0:2</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">M</font> being   <a href="matroid0.html#V1" title="MATROID0:attr.1">subset-closed</a>  <a href="matroid0.html#NM1" title="MATROID0:NM.1">SubsetFamilyStr</a> holds <br/> (  not <font color="Olive" title="b1">M</font> is  <a href="pencil_1.html#V3" title="PENCIL_1:attr.3">void</a>  iff  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="tarski.html#R2" title="TARSKI:pred.2">in</a>  <a href="matroid0.html#K1" title="MATROID0:func.1">the_family_of</a> <font color="Olive" title="b1">M</font> )</div></div>
