LIST-TO-SET
===========

syntax: (list-to-set <evaluates-to list>
                     [:TYPE <evaluates-to type-name>]
                     [:TEST <lisp-type: function>])

        ==> #<set-of X (...)>

This function produces a set with the given 
elements.

Warning: type checking may cause an error!

example: >(list-to-set 
            (list Paris Dortmund Bruessel 
                 Bonn Berlin))
         #<set-of T (...)>
      
         >(setf *cities*
            (list-to-set
               (list Paris Dortmund Bruessel 
                    Bonn Berlin)
               :TYPE 'CITY))
         #<set-of CITY (...)>

         >(setf *capital-cities*
            (list-to-set
               (list Paris Dortmund Bruessel 
                      Bonn Berlin)
               :TYPE 'CAPITAL-CITY))
         #<set-of CAPITAL-CITY (...)>