Private Sub InterestPaymentVerify()
    'Verify that the InterestPayment function works correctly.

    Debug.Assert Approx(InterestPayment(0.1, 1, 5, 10000, 0, 0), -1000)
    Debug.Assert Approx(InterestPayment(0.1, 2, 5, 10000, 0, 0), -836.202519205254)
    Debug.Assert Approx(InterestPayment(0.1, 3, 5, 10000, 0, 0), -656.025290331035)
    Debug.Assert Approx(InterestPayment(0.1, 4, 5, 10000, 0, 0), -457.830338569393)
    Debug.Assert Approx(InterestPayment(0.1, 5, 5, 10000, 0, 0), -239.815891631587)

    Debug.Assert Approx(InterestPayment(0.1, 1, 5, 10000, 0, 1), 0)
    Debug.Assert Approx(InterestPayment(0.1, 2, 5, 10000, 0, 1), -760.184108368413)
    Debug.Assert Approx(InterestPayment(0.1, 3, 5, 10000, 0, 1), -596.386627573668)
    Debug.Assert Approx(InterestPayment(0.1, 4, 5, 10000, 0, 1), -416.209398699448)
    Debug.Assert Approx(InterestPayment(0.1, 5, 5, 10000, 0, 1), -218.014446937806)

    Debug.Assert Approx(InterestPayment(0.1, 1, 5, 10000, 2000, 0), -1000)
    Debug.Assert Approx(InterestPayment(0.1, 2, 5, 10000, 2000, 0), -803.443023046305)
    Debug.Assert Approx(InterestPayment(0.1, 3, 5, 10000, 2000, 0), -587.230348397242)
    Debug.Assert Approx(InterestPayment(0.1, 4, 5, 10000, 2000, 0), -349.396406283271)
    Debug.Assert Approx(InterestPayment(0.1, 5, 5, 10000, 2000, 0), -87.7790699579042)

    Debug.Assert Approx(InterestPayment(0.1, 1, 5, 10000, 2000, 1), 0)
    Debug.Assert Approx(InterestPayment(0.1, 2, 5, 10000, 2000, 1), -730.402748223914)
    Debug.Assert Approx(InterestPayment(0.1, 3, 5, 10000, 2000, 1), -533.84577127022)
    Debug.Assert Approx(InterestPayment(0.1, 4, 5, 10000, 2000, 1), -317.633096621156)
    Debug.Assert Approx(InterestPayment(0.1, 5, 5, 10000, 2000, 1), -79.7991545071856)

    Debug.Assert Approx(InterestPayment(0, 1, 5, 10000, 2000, 0), 0)
    Debug.Assert Approx(InterestPayment(0, 3, 5, 10000, 2000, 0), 0)
    Debug.Assert Approx(InterestPayment(0, 5, 5, 10000, 2000, 0), 0)

    Debug.Assert Approx(InterestPayment(0, 1, 5, 10000, 2000, 1), 0)
    Debug.Assert Approx(InterestPayment(0, 3, 5, 10000, 2000, 1), 0)
    Debug.Assert Approx(InterestPayment(0, 5, 5, 10000, 2000, 1), 0)

End Sub