<?xml version="1.0"?>
<div class="add">

<b>let </b><font color="Maroon">A</font> be    <a href="hidden.html#M1">set</a> ;<br/>

<a NAME="E1:79"/>
 <a href="xboole_0.html#K1">{}</a>  <a href="hidden.html#R2">in</a>  <a href="normform.html#K8" target="_self">Normal_forms_on</a> <font color="Maroon">A</font>
 
<b>by </b><i><a class="ref" href="normform.html#T22" target="_self">Th22</a></i>;<br/>
<b>then reconsider </b><font color="Maroon">Z</font> =  <a href="xboole_0.html#K1">{}</a>  as   <a href="struct_0.html#NM1">Element</a> of <span class="p1">(<span class="default"><a href="normform.html#K12" target="_self">NormForm</a> <font color="Maroon">A</font></span>)</span> <b>by </b><i/>;<br/>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="79_1"><b>now </b></a><div class="add"><b>let </b><font color="Maroon">u</font> be   <a href="struct_0.html#NM1">Element</a> of <span class="p1">(<span class="default"><a href="normform.html#K12" target="_self">NormForm</a> <font color="Maroon">A</font></span>)</span>;<br/><b>reconsider </b><font color="Maroon">z</font> = <font color="Maroon">Z</font>, <font color="Maroon">u'</font> = <font color="Maroon">u</font> as    <a href="subset_1.html#M2">Element</a> of  <a href="normform.html#K8" target="_self">Normal_forms_on</a> <font color="Maroon">A</font> <b>by </b><i/>;<br/><b>thus </b><font color="Maroon">Z</font> <a href="lattices.html#K3">"\/"</a> <font color="Maroon">u</font> = 
 <a href="normform.html#K9" target="_self">mi</a> <span class="p1">(<span class="default"><font color="Maroon">z</font> <a href="setwiseo.html#K5">\/</a> <font color="Maroon">u'</font></span>)</span>
<b>by </b><i/>
<br/>.= 
<font color="Maroon">u</font>
<b>by </b><i/>
;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E4:79"/>
 <a href="lattices.html#K5">Bottom</a> <span class="p1">(<span class="default"><a href="normform.html#K12" target="_self">NormForm</a> <font color="Maroon">A</font></span>)</span> <a href="hidden.html#R1">=</a>  <a href="xboole_0.html#K1">{}</a> 
 <b>by </b><i><a class="ref" href="lattice2.html#T21">LATTICE2:21</a></i>;<br/>


</div>
