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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E25">Th18</font></span>: <a NAME="T25"><span class="comment"><font color="firebrick">:: QUATERNI:25</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">z1</font>, <font color="Olive" title="b2">z2</font> being   <a href="quaterni.html#V1" title="QUATERNI:attr.1">quaternion</a>   <a href="ordinal1.html#NM2" title="ORDINAL1:NM.2">number</a>   st  <a href="quaterni.html#K12" title="QUATERNI:func.12">Rea</a> <font color="Olive" title="b1">z1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="quaterni.html#K12" title="QUATERNI:func.12">Rea</a> <font color="Olive" title="b2">z2</font> &amp;  <a href="quaterni.html#K13" title="QUATERNI:func.13">Im1</a> <font color="Olive" title="b1">z1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="quaterni.html#K13" title="QUATERNI:func.13">Im1</a> <font color="Olive" title="b2">z2</font> &amp;  <a href="quaterni.html#K14" title="QUATERNI:func.14">Im2</a> <font color="Olive" title="b1">z1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="quaterni.html#K14" title="QUATERNI:func.14">Im2</a> <font color="Olive" title="b2">z2</font> &amp;  <a href="quaterni.html#K15" title="QUATERNI:func.15">Im3</a> <font color="Olive" title="b1">z1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="quaterni.html#K15" title="QUATERNI:func.15">Im3</a> <font color="Olive" title="b2">z2</font> holds <br/><font color="Olive" title="b1">z1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b2">z2</font></div></div>
