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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E42">Th53</font></span>: <a NAME="T53"><span class="comment"><font color="firebrick">:: TOPGEN_5:53</font></span><br/></a><div class="add"> <a href="topgen_3.html#K2" title="TOPGEN_3:func.2">Sorgenfrey-line</a>  is  <a href="pre_topc.html#V7" title="PRE_TOPC:attr.7">T_1</a> </div></div>
