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<b>let </b><font color="Maroon">L</font> be   <a href="lattices.html#NM1">Lattice</a>;<br/><b>let </b><font color="Maroon">v</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">L</font>;<br/><b>let </b><font color="Maroon">A</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">B</font> be   <a href="finsub_1.html#NM1">Finite_Subset</a> of <font color="Maroon">A</font>;<br/><b>let </b><font color="Maroon">f</font> be   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">A</font>,the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">L</font>;<br/>









<b>assume </b><a NAME="E1:49"/><i><font color="Green">E17</font></i>: 
<font color="Maroon">B</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 ;<br/>

<b>set </b><font color="Maroon">J</font> = the <a href="lattices.html#U2">L_join</a> of <font color="Maroon">L</font>;<br/>
<a NAME="E2:49"/><i><font color="Green">E18</font></i>: 
( the <a href="lattices.html#U2">L_join</a> of <font color="Maroon">L</font> is <a href="binop_1.html#V3">idempotent</a> &amp; the <a href="lattices.html#U2">L_join</a> of <font color="Maroon">L</font> is <a href="binop_1.html#V1">commutative</a> &amp; the <a href="lattices.html#U2">L_join</a> of <font color="Maroon">L</font> is <a href="binop_1.html#V2">associative</a> &amp; the <a href="lattices.html#U2">L_join</a> of <font color="Maroon">L</font> <a href="binop_1.html#R6">is_distributive_wrt</a> the <a href="lattices.html#U2">L_join</a> of <font color="Maroon">L</font> )
 
<b>by </b><i><a class="txt" href="lattice2.html#E1:49"><i><font color="Green">E17</font></i></a>, <a class="ref" href="lattice2.html#T7" target="_self">Th7</a></i>;<br/>
<b>thus </b><a NAME="E3:49"/>
<font color="Maroon">v</font> <a href="lattices.html#K3">"\/"</a> <span class="p1">(<span class="default"><a href="lattice2.html#K2" target="_self">FinJoin</a> <font color="Maroon">B</font>,<font color="Maroon">f</font></span>)</span> <a href="hidden.html#R1">=</a>  <a href="lattice2.html#K2" target="_self">FinJoin</a> <font color="Maroon">B</font>,<span class="p1">(<span class="default">the <a href="lattices.html#U2">L_join</a> of <font color="Maroon">L</font> <a href="funcop_1.html#K8">[;]</a> <font color="Maroon">v</font>,<font color="Maroon">f</font></span>)</span>
 <b>by </b><i>, , <a class="ref" href="setwiseo.html#T36">SETWISEO:36</a></i>;<br/>


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