& setunion()
 
  Syntax: setunion(<list1>, <list2>[, <delim>])
 
  This function returns the union of two sets -- i.e., all the 
  elements of both <list1> and <list2>, minus any duplicate elements. 
  Think of it as cat() without duplicated words. The list returned is 
  sorted. If <delim> is specified, it (rather than a space) is used 
  to separate item in the list.
 
  Example:
  > say setunion(foo baz gleep bar, bar moof gleep)
  You say, "bar baz foo gleep moof"
 
	See Also: setdiff(), setinter(), sort()