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<div><span class="kw">theorem </span><a NAME="T27"><span class="comment"><font color="firebrick">:: ORDINAL4:27</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> being   <a href="ordinal1.html#NM3" title="ORDINAL1:NM.3">Ordinal</a>  st <font color="Olive" title="b3">C</font> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  &amp; <font color="Olive" title="b1">A</font> <a href="ordinal1.html#R1" title="ORDINAL1:pred.1">c=</a> <font color="Olive" title="b2">B</font> holds <br/> <a href="ordinal2.html#K12" title="ORDINAL2:func.12">exp</a> (<font color="Olive" title="b3">C</font>,<font color="Olive" title="b1">A</font>) <a href="ordinal1.html#R1" title="ORDINAL1:pred.1">c=</a>  <a href="ordinal2.html#K12" title="ORDINAL2:func.12">exp</a> (<font color="Olive" title="b3">C</font>,<font color="Olive" title="b2">B</font>)</div></div>
