RULESET-OF
==========

syntax: (ruleset-of <rule-specifier>
                    [:IDENTIFIER T | NIL | Var]
                    [:KB <kb>])

Warning: Two rules with the same names can exist in
         different sets! Hence first hit. Here the
         emulation can refuse, because B3 works here
         with instances!
         The key :KB is unsupported yet!

This function returns the set of rules, which contains
the given rule. If you set ':IDENTIFIER' to T, then
you get back the name of the set of rules. If you set
':IDENTIFIER' to NIL, then the set of rules will be
returned as an object.

example: >(ruleset-of '(holidayoffer holidayselection)
                      :identifier T)
         HOLIDAYOFFER