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<b>let </b><font color="Maroon">c<sub>1</sub></font> be  non <a href="struct_0.html#V3">empty</a> <a href="lattices.html#V10">Lattice-like</a> <a href="lattices.html#V17">Boolean</a> <a href="robbins1.html#V7">well-complemented</a> <a href="sheffer1.html#V9" target="_self">properly_defined</a>  <a href="sheffer1.html#L3" target="_self">ShefferOrthoLattStr</a> ;<br/><b>let </b><font color="Maroon">c<sub>2</sub></font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">c<sub>1</sub></font>; <i><font color="Red">:: according to </font></i><a class="ref" href="sheffer1.html#D13" target="_self">SHEFFER1:def 13</a><br/>



<a NAME="E1:50"/>
<span class="p1">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="robbins1.html#K3">`</a> </span>)</span> <a href="robbins1.html#K3">`</a>  <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font>
 
<b>by </b><i><a class="ref" href="robbins1.html#T3">ROBBINS1:3</a></i>;<br/>
<a NAME="E2:50"/><b>then </b>
<span class="p1">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="sheffer1.html#K5" target="_self">|</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="robbins1.html#K3">`</a>  <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font>
 
<b>by </b><i><a class="ref" href="sheffer1.html#D12" target="_self">Def12</a></i>;<br/>
<b>hence </b><a NAME="E3:50"/>
<span class="p1">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="sheffer1.html#K5" target="_self">|</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="sheffer1.html#K5" target="_self">|</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="sheffer1.html#K5" target="_self">|</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font>
 <b>by </b><i><a class="ref" href="sheffer1.html#D12" target="_self">Def12</a></i>;<br/>


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