MODULE Demo
    IMPLICIT NONE
    TYPE My_complex
        INTEGER :: real, imaginary
    END TYPE My_complex

CONTAINS

    PURE FUNCTION add (X, Y)
        IMPLICIT NONE
        TYPE(My_complex) :: add
        TYPE(My_complex), INTENT(IN) :: X, Y

        add%real = X%real+Y%real
        add%imaginary = X%imaginary+Y%imaginary
    END FUNCTION add

END MODULE Demo