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<b>let </b><font color="Maroon">V</font> be  non <a href="xboole_0.html#V1">empty</a>  <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">C</font> be  non <a href="xboole_0.html#V1">empty</a> <a href="finset_1.html#V1">finite</a>  <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">A</font> be    <a href="subset_1.html#M2">Element</a> of  <a href="substlat.html#K1">SubstitutionSet</a> <font color="Maroon">V</font>,<font color="Maroon">C</font>;<br/>





<b>assume </b><a NAME="E1:24"/>
<font color="Maroon">A</font> <a href="hidden.html#R1">=</a>  <a href="xboole_0.html#K1">{}</a> 
 ;<br/>

<a NAME="E2:24"/><b>then </b><i><font color="Green">E21</font></i>: 
 <a href="heyting2.html#K2" target="_self">-</a> <font color="Maroon">A</font> <a href="hidden.html#R1">=</a> <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><a href="xboole_0.html#K1">{}</a> </span><a href="tarski.html#K1">}</a></span>
 
<b>by </b><i/>;<br/>
<a NAME="E3:24"/><b>then </b>
 <a href="heyting2.html#K2" target="_self">-</a> <font color="Maroon">A</font> <a href="hidden.html#R2">in</a>  <a href="substlat.html#K1">SubstitutionSet</a> <font color="Maroon">V</font>,<font color="Maroon">C</font>
 
<b>by </b><i><a class="ref" href="substlat.html#T2">SUBSTLAT:2</a></i>;<br/>
<a NAME="E4:24"/><b>then </b>
 <a href="substlat.html#K3">mi</a> <span class="p1">(<span class="default"><a href="heyting2.html#K2" target="_self">-</a> <font color="Maroon">A</font></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><a href="xboole_0.html#K1">{}</a> </span><a href="tarski.html#K1">}</a></span>
 
<b>by </b><i>, <a class="ref" href="substlat.html#T11">SUBSTLAT:11</a></i>;<br/>
<b>hence </b><a NAME="E5:24"/>
 <a href="substlat.html#K3">mi</a> <span class="p1">(<span class="default"><a href="heyting2.html#K2" target="_self">-</a> <font color="Maroon">A</font></span>)</span> <a href="hidden.html#R1">=</a>  <a href="lattices.html#K6">Top</a> <span class="p1">(<span class="default"><a href="substlat.html#K5">SubstLatt</a> <font color="Maroon">V</font>,<font color="Maroon">C</font></span>)</span>
 <b>by </b><i><a class="ref" href="substlat.html#T27">SUBSTLAT:27</a></i>;<br/>


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