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<b>let </b><font color="Maroon" title="c1">L</font> be  non <a href="struct_0.html#V3" title="STRUCT_0:attr.3">empty</a>  <a href="sheffer1.html#L3" title="SHEFFER1:struct.3">ShefferOrthoLattStr</a> ;<br/>

<b>assume </b><a NAME="E1:168_2_1"/>
( <font color="Maroon" title="c1">L</font> is <a href="lattices.html#V17" title="LATTICES:attr.17">Boolean</a> &amp; <font color="Maroon" title="c1">L</font> is <a href="lattices.html#V10" title="LATTICES:attr.10">Lattice-like</a> &amp; <font color="Maroon" title="c1">L</font> is <a href="robbins1.html#V7" title="ROBBINS1:attr.7">well-complemented</a> &amp; <font color="Maroon" title="c1">L</font> is <a href="sheffer1.html#V9" title="SHEFFER1:attr.9">properly_defined</a> )
 ;<br/>

<b>then reconsider </b><font color="Maroon" title="c2">L'</font> = <font color="Maroon" title="c1">L</font> as  non <a href="struct_0.html#V3" title="STRUCT_0:attr.3">empty</a> <a href="lattices.html#V10" title="LATTICES:attr.10">Lattice-like</a> <a href="lattices.html#V17" title="LATTICES:attr.17">Boolean</a> <a href="robbins1.html#V7" title="ROBBINS1:attr.7">well-complemented</a> <a href="sheffer1.html#V9" title="SHEFFER1:attr.9">properly_defined</a>  <a href="sheffer1.html#L3" title="SHEFFER1:struct.3">ShefferOrthoLattStr</a>  ;<br/>
<a NAME="E3:168_2_1"/>
<font color="Maroon" title="c2">L'</font> is <a href="sheffer2.html#V1" title="SHEFFER2:attr.1">satisfying_Sh_1</a>
 
;<br/>
<b>hence </b><a NAME="E4:168_2_1"/>
<font color="Maroon" title="c1">L</font> is <a href="sheffer2.html#V1" title="SHEFFER2:attr.1">satisfying_Sh_1</a>
 ;<br/>


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