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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E18">Th15</font></span>: <a NAME="T15"><span class="comment"><font color="firebrick">:: INTEGRA8:15</font></span><br/></a><div class="add"> <a href="sin_cos6.html#K4" title="SIN_COS6:func.4">arccos</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="square_1.html#K3" title="SQUARE_1:func.3">sqrt</a> 2</span>)</span> <a href="xcmplx_0.html#K7" title="XCMPLX_0:func.7">/</a> 2</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <a href="sin_cos.html#K28" title="SIN_COS:func.28">PI</a> <a href="xcmplx_0.html#K7" title="XCMPLX_0:func.7">/</a> 4</div></div>
