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<div><span class="kw">theorem </span><a NAME="T13"><span class="comment"><font color="firebrick">:: QUATERNI:13</font></span><br/></a><div class="add"><a href="xcmplx_0.html#K1" title="XCMPLX_0:func.1">&lt;i&gt;</a> <a href="quaterni.html#K9" title="QUATERNI:func.9">*</a> <a href="xcmplx_0.html#K1" title="XCMPLX_0:func.1">&lt;i&gt;</a> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xcmplx_0.html#K4" title="XCMPLX_0:func.4">-</a> 1</div></div>
