// @(#)$Id: Set.pri,v 1.2 1997/01/05 01:54:34 leavens Exp $
// private members of class Set

private:
  List<T>* elems;
  // rep invariant: notNull(elems);
  // abstraction function: A(*this) =
  //                        if isEmpty(*elems) then {}
  //                        else {head(*elems)} \U A(tail(*elems))