Relation pm#member (collection,*)
  supertype:  relation_from_collection  wnMember
  subtype:  domain_object (domain,?)
     subtype:  core_domain_object__central_object_of_domain (domain,?)
  subtype:  reverse_of_KIF_member (set,?)  this type only exists to make the connection to kif#member (which should have been named kif#member_of to respect the common reading conventions of parameters)
  subtype:  item (list,?)
     subtype:  item (list,?)  for item(L,I) read: I is an item in L; either first(L,I) or item(R,I) where rest(L,R)
  subtype:  li (collection,*)
  subtype:  first (list -> ?)
     subtype:  first (list -> ?)
  subtype:  last (list -> ?)
  subtype:  butlast (list -> ?)
  subtype:  nth (list,positive_integer -> ?)