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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E20">Th19</font></span>: <a NAME="T19"><span class="comment"><font color="firebrick">:: SRINGS_5:19</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">n</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a> holds   <a href="tarski.html#K3" title="TARSKI:func.3">union</a> <span class="p1">(<span class="default"><a href="srings_5.html#K7" title="SRINGS_5:func.7">OpenHypercubesRAT</a> <font color="Olive" title="b1">n</font></span>)</span> is   <a href="tops_2.html#V1" title="TOPS_2:attr.1">open</a>  <a href="struct_0.html#NM3" title="STRUCT_0:NM.3">Subset-Family</a> of <span class="p1">(<span class="default"><a href="euclid.html#K15" title="EUCLID:func.15">TOP-REAL</a> <font color="Olive" title="b1">n</font></span>)</span></div></div>
