PROGRAM Run
    USE Demo
    IMPLICIT NONE
    TYPE(My_complex) :: one = My_complex(123, 456), &
        two = My_complex(432, 876), three, four

    three = one
    four%imaginary = two%real
    four%real = two%imaginary
    WRITE (*, '("( ", I0, " , ", I0, " )")')  &
        add(one,add(two,add(three,four)))
END PROGRAM Run