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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E24">Th18</font></span>: <a NAME="T18"><span class="comment"><font color="firebrick">:: XXREAL_0:18</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">a</font>, <font color="Olive" title="b2">b</font>, <font color="Olive" title="b3">c</font>, <font color="Olive" title="b4">d</font> being   <a href="xxreal_0.html#NM1" title="XXREAL_0:NM.1">ExtReal</a>  st <font color="Olive" title="b1">a</font> <a href="xxreal_0.html#R1" title="XXREAL_0:pred.1">&lt;=</a> <font color="Olive" title="b2">b</font> &amp; <font color="Olive" title="b3">c</font> <a href="xxreal_0.html#R1" title="XXREAL_0:pred.1">&lt;=</a> <font color="Olive" title="b4">d</font> holds <br/> <a href="xxreal_0.html#K3" title="XXREAL_0:func.3">min</a> (<font color="Olive" title="b1">a</font>,<font color="Olive" title="b3">c</font>) <a href="xxreal_0.html#R1" title="XXREAL_0:pred.1">&lt;=</a>  <a href="xxreal_0.html#K3" title="XXREAL_0:func.3">min</a> (<font color="Olive" title="b2">b</font>,<font color="Olive" title="b4">d</font>)</div></div>
