IS-FRAME-OF
===========

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

Warning: under construction: the key :KB
         is unsupported yet!

This function tests, whether the given instance be-
longs to the given frame. If you do not give details, 
then T will be returned if <frame-specifier> is the 
frame of the instance, respectively is the superframe
from the instance's frame. Otherwise NIL will be
returned.

example: >(is-frame-of Berlin 'capitalcity)
         T
         >(is-frame-of Berlin 'city)
         T
         >(is-frame-of Berlin 'city :direct T)
         NIL