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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E28">Th19</font></span>: <a NAME="T19"><span class="comment"><font color="firebrick">:: STACKS_1:19</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">X</font> being   <a href="stacks_1.html#NM3" title="STACKS_1:NM.3">StackAlgebra</a><br/>  for <font color="Olive" title="b2">s</font> being   <a href="stacks_1.html#NM2" title="STACKS_1:NM.2">stack</a> of <font color="Olive" title="b1">X</font>  st  <a href="stacks_1.html#R1" title="STACKS_1:pred.1">emp</a> <font color="Olive" title="b2">s</font> holds <br/> <a href="eqrel_1.html#K6" title="EQREL_1:func.6">Class</a> (<span class="p1">(<span class="default"><a href="stacks_1.html#K10" title="STACKS_1:func.10">==_</a> <font color="Olive" title="b1">X</font></span>)</span>,<font color="Olive" title="b2">s</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  the <a href="stacks_1.html#U1" title="STACKS_1:sel.1">s_empty</a> of <font color="Olive" title="b1">X</font></div></div>
