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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E11">Th11</font></span>: <a NAME="T12"><span class="comment"><font color="firebrick">:: TREES_1:12</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">p</font>, <font color="Olive" title="b2">q</font> being   <a href="finseq_1.html#NM1" title="FINSEQ_1:NM.1">FinSequence</a> holds <br/> ( <font color="Olive" title="b1">p</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a>  <a href="trees_1.html#K1" title="TREES_1:func.1">ProperPrefixes</a> <font color="Olive" title="b2">q</font> iff <font color="Olive" title="b1">p</font> <a href="trees_1.html#NR3" title="TREES_1:NR.3">is_a_proper_prefix_of</a> <font color="Olive" title="b2">q</font> )</div></div>
