&lt;=&gt; to
&gt; &gt; &gt; what follows the &lt;=&gt; a "reduction".
&gt; &gt; 
&gt; &gt; MW:  Indeed, the only thing that is reduced is the arity
&gt;        of the relations used.  On the other hand we do have
&gt;        a more accurate model.
&gt; 
&gt;                   ^^^
&gt; False statement.  |||
&gt; 
&gt; Because I still believe that you really want to know.
&gt; 
&gt; Exercise for the reader:
&gt; 
&gt; What is the arity of the first "and" relation
&gt; that is invoked in the above bit of kiffa