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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">p</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">L</font>;<br/><b>let </b><font color="Maroon">r</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">L</font>;<br/><b>let </b><font color="Maroon">q</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">L</font>;<br/>







<b>assume </b><a NAME="E1:2"/>
<font color="Maroon">p</font> <a href="lattices.html#R3">[=</a> <font color="Maroon">r</font>
 ;<br/>

<a NAME="E2:2"/><b>then </b>
( <font color="Maroon">p</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">q</font> <a href="lattices.html#R3">[=</a> <font color="Maroon">r</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">q</font> &amp; <font color="Maroon">q</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">p</font> <a href="lattices.html#R3">[=</a> <font color="Maroon">q</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">r</font> &amp; <font color="Maroon">r</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">q</font> <a href="lattices.html#R3">[=</a> <font color="Maroon">r</font> &amp; <font color="Maroon">q</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">r</font> <a href="hidden.html#R1">=</a> <font color="Maroon">r</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">q</font> )
 
<b>by </b><i><a class="ref" href="lattices.html#T23">LATTICES:23</a>, <a class="ref" href="lattices.html#T27">LATTICES:27</a></i>;<br/>
<b>hence </b><a NAME="E3:2"/>
<font color="Maroon">p</font> <a href="lattices.html#K4">"/\"</a> <font color="Maroon">q</font> <a href="lattices.html#R3">[=</a> <font color="Maroon">r</font>
 <b>by </b><i><a class="ref" href="lattices.html#T25">LATTICES:25</a></i>;<br/>


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