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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E19">Th17</font></span>: <a NAME="T17"><span class="comment"><font color="firebrick">:: RFUNCT_3:17</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>  holds   <a href="binop_1.html#K3" title="BINOP_1:func.3">the_unity_wrt</a> <span class="p1">(<span class="default"><a href="rfunct_3.html#K13" title="RFUNCT_3:func.13">addpfunc</a> <font color="Olive" title="b1">D</font></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default"><a href="subset_1.html#K2" title="SUBSET_1:func.2">[#]</a> <font color="Olive" title="b1">D</font></span>)</span> <a href="funcop_1.html#K7" title="FUNCOP_1:func.7">--&gt;</a> <a href="numbers.html#K5" title="NUMBERS:func.5">0</a></div></div>
