ADD-DEPENDENT
=============

syntax: (add-dependent <relation-specifier>
                       <sender-specifier>
                       <receiver-specifier>
                       {[:READ T | NIL | var]
                        [:WRITE T | NIL | var]}+
                       [:KB <kb>])

Warning: yet not implemented!

Read- and write-dependents will be added dynamically.
With the optional parameters you can set the dependent
to be a read- and/or a write-dependent. If you only
want to send a read-dependent message, then you have
to set ':READ T'. For only write-dependent messages you
have to set ':WRITE T'.
The behaviors NOTIFY-READ-DEPENDENT or NOTIFY-WRITE-
DEPENDENT are necessary for the process.

If the receiver of the message - in our case RECEIVER-
SPECIFIER - is not included yet, then he will be 
returned as a value, otherwise NIL.
If you put in the identifier, you get back the name of 
the instance. If you put in the object, you get back 
the object.

example: >(add-dependent 'place Louvre
                         trafficoffice-Paris :read T)
         #<TRAFFICOFFICE TRAFFICOFFICE-PARIS>

         or

         >(add-dependent 'place 'Louvre
                         'trafficoffice-Paris :read T)
         TRAFFICOFFICE-PARIS