different stages.\
&gt; &gt;    * There are no identity conditions that can be used to identify
&gt; &gt;      two occurrents that are observed in nonoverlapping space-time 
&gt; regions. \
&gt; &gt;
&gt; &gt; (NOTE:  The notions identity conditions and observation are not axiomatized
&gt; &gt;  in this ontology, so this is not an actual axiom of the ontology, 
&gt; unlike the
&gt; &gt;  two axioms above.  (Though those two required adding some notions that 
&gt; are only
&gt; &gt;  implicit in Sowa's ontol