INSTANCES-OF
============

syntax: (instances-of <frame-specifier>
                      [:DIRECT T | NIL | Var]
                      [:IDENTIFIER T | NIL | Var]
                      [:KB <kb>])

This function returns a list with static instance
objects or instance identifiers of a frame. Dynamic
instances cannot be found this way! If you do
not give any details, then ':DIRECT' AND ':IDENTIFIER' 
will be set to NIL and you will get a list with all 
instances of the frame as objects.

example: >(instances-of 'city)
         (#<CAPITALCITY PARIS> #<CAPITALCITY LONDON>
             #<CAPITALCITY NEW-YORK> 
                   #<CAPITALCITY BERLIN>)