<?xml version="1.0"?>
<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E18">Th17</font></span>: <a NAME="T18"><span class="comment"><font color="firebrick">:: EUCLID_7:18</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">B0</font> being   <a href="subset_1.html#NM2" title="SUBSET_1:NM.2">Subset</a> of <span class="p1">(<span class="default"><a href="euclid.html#K1" title="EUCLID:func.1">REAL</a> <a href="numbers.html#K5" title="NUMBERS:func.5">0</a></span>)</span>  st <font color="Olive" title="b1">B0</font> is  <a href="euclid_7.html#V5" title="EUCLID_7:attr.5">orthogonal_basis</a>  holds <br/><font color="Olive" title="b1">B0</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> </div></div>
