TYPE queue = liste;

PROCEDURE enqueue(x: atom; VAR q: queue);
VAR p: queue;
BEGIN NEW(p); 
      IF q = NIL THEN q := p ELSE p^.nach := q^.nach
      END; 
      q^.nach := p; q := p; p^.wert := x; 
END enqueue;

PROCEDURE dequeue(VAR x: atom; VAR q: queue);
VAR p: queue;
BEGIN p := q^.nach; x := p^.wert; 
      IF q = p THEN q := NIL ELSE q^.nach := p^.nach
      END;
      DISPOSE(p);
END dequeue;