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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E15">Th13</font></span>: <a NAME="T13"><span class="comment"><font color="firebrick">:: CATALG_1:13</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">a1</font>, <font color="Olive" title="b2">b1</font>, <font color="Olive" title="b3">a2</font>, <font color="Olive" title="b4">b2</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>   st  <a href="catalg_1.html#K6" title="CATALG_1:func.6">homsym</a> (<font color="Olive" title="b1">a1</font>,<font color="Olive" title="b3">a2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="catalg_1.html#K6" title="CATALG_1:func.6">homsym</a> (<font color="Olive" title="b2">b1</font>,<font color="Olive" title="b4">b2</font>) holds <br/>( <font color="Olive" title="b1">a1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b2">b1</font> &amp; <font color="Olive" title="b3">a2</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">b2</font> )</div></div>
