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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E51">Th153</font></span>: <a NAME="T153"><span class="comment"><font color="firebrick">:: ZF_LANG1:153</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">x1</font>, <font color="Olive" title="b2">x2</font>, <font color="Olive" title="b3">y1</font>, <font color="Olive" title="b4">y2</font> being   <a href="zf_lang.html#NM1" title="ZF_LANG:NM.1">Variable</a>  ex <font color="Olive" title="b5">z1</font>, <font color="Olive" title="b6">z2</font> being   <a href="zf_lang.html#NM1" title="ZF_LANG:NM.1">Variable</a> st <span class="p1">(<span class="default"><font color="Olive" title="b1">x1</font> <a href="zf_lang.html#K3" title="ZF_LANG:func.3">'='</a> <font color="Olive" title="b2">x2</font></span>)</span> <a href="zf_lang1.html#K5" title="ZF_LANG1:func.5">/</a> (<font color="Olive" title="b3">y1</font>,<font color="Olive" title="b4">y2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">z1</font> <a href="zf_lang.html#K3" title="ZF_LANG:func.3">'='</a> <font color="Olive" title="b6">z2</font></div></div>
