MODULE Summer
    IMPLICIT NONE
    REAL, SAVE :: fred = 0.0, joe = 0.0, bill = 0.0
END MODULE Summer

MODULE Summer_A
CONTAINS
    SUBROUTINE A
        USE Summer, ONLY : fred
        IMPLICIT NONE
        fred = fred+1.23
    END SUBROUTINE A
END MODULE Summer_A

MODULE Summer_B
CONTAINS
    SUBROUTINE B
        USE Summer, ONLY : fred, joe
        IMPLICIT NONE
        joe = fred+0.7
    END SUBROUTINE B
END MODULE Summer_B

MODULE Summer_C
CONTAINS
    SUBROUTINE C
        USE Summer, ONLY : fred, joe, bill
        IMPLICIT NONE
        bill = fred+joe
    END SUBROUTINE C
END MODULE Summer_C

MODULE Summer_D
CONTAINS
    SUBROUTINE D
        USE Summer, ONLY : bill
        IMPLICIT NONE
        PRINT *, bill
    END SUBROUTINE D
END MODULE Summer_D