 
&gt; This is closely connected with a rather tricky technical issue in the 
&gt; semantics of the new KIF, which arises from the fact that it is legal 
&gt; (in the new KIF) to say that a predicate is true of itself. We argued 
&gt; about this for a while, but it seems clear that the language can be 
&gt; given a uniform, consistent semantics which allow unlimited 
&gt; self-application of classes, predicates, relations or sorts. The 
&gt; basic technique for doing this was provided by Chris Menzel. 
&gt;