Sortierte Listen auf Basis von verzeigerten Elementen II

PROCEDURE InitListOfAppointments
            (VAR list: ListOfAppointments);
BEGIN
   list.first := NIL; list.length := 0; list.cursor := NIL;
END InitListOfAppointments;

PROCEDURE GetFirstAppointment(list: ListOfAppointments;
                              VAR appointment: Appointment);
BEGIN
   ASSERT(list.length > 0);
   appointment := list.first.appointment;
END GetFirstAppointment;

PROCEDURE NumberOfAppointments
            (list: ListOfAppointments) : INTEGER;
BEGIN
   RETURN list.length
END NumberOfAppointments;