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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E17">Th18</font></span>: <a NAME="T18"><span class="comment"><font color="firebrick">:: JORDAN4:18</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">D</font> being   non  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>   <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b2">f1</font> being    <a href="finseq_1.html#M2" title="FINSEQ_1:mode.2">FinSequence</a> of <font color="Olive" title="b1">D</font><br/>  for <font color="Olive" title="b3">i1</font>, <font color="Olive" title="b4">i2</font> being   <a href="nat_1.html#NM1" title="NAT_1:NM.1">Nat</a> holds   <a href="finseq_6.html#K3" title="FINSEQ_6:func.3">mid</a> (<font color="Olive" title="b2">f1</font>,<font color="Olive" title="b3">i1</font>,<font color="Olive" title="b4">i2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="finseq_5.html#K4" title="FINSEQ_5:func.4">Rev</a> <span class="p1">(<span class="default"><a href="finseq_6.html#K3" title="FINSEQ_6:func.3">mid</a> (<font color="Olive" title="b2">f1</font>,<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b3">i1</font>)</span>)</span></div></div>
