DEPENDENTS-OF
=============

syntax: (dependents-of <relation-specifier>
                       <instance-specifier>
                       {[:READ T | NIL | Var]
                        [:WRITE T | NIL | Var]}+
                       [:IDENTIFIER T | NIL | Var]
                       [:KB <kb>])

Warning: yet not implemented!

This function returns the read- and/or write-
dependents of an instance relation. If you want to 
have all read-dependent receivers, then you have to 
set ':READ' to T. If you only want to have write-
dependent receivers, then ':WRITE' has to be set to T.
The list of dependents will be returned as objects 
or as identifiers.

example: >(dependents-of 'place museum :read T)
         (#<TRAFFICOFFICE TRAFFICOFFICE-PARIS>)