 Occurrent)
&gt; &gt;
&gt; &gt; (documentation "AXIOM: Each spatial part of an occurrent exists at some 
&gt; location.")
&gt; &gt;
&gt; &gt; (forall (?occ ?x)
&gt; &gt;         (=&gt; (and (instance-of ?occ Occurrent)
&gt; &gt;                  (spatial-part-of ?x ?occ))
&gt; &gt;             (exists (?loc)
&gt; &gt;                     (located-at ?x ?loc))))
&gt; &gt;
&gt; &gt; (documentation "AXIOM:  Occurrents have temporal parts")
&gt; &gt;
&gt; &gt; (forall (?occ)
&gt; &gt;         (=&gt; (instance-o