Private Function ModAltVerify()
    ' Test the ModAlt function.

    Debug.Assert ModAlt(5, 3) = 2
    Debug.Assert ModAlt(4, 3) = 1
    Debug.Assert ModAlt(3, 3) = 0
    Debug.Assert ModAlt(2, 3) = 2
    Debug.Assert ModAlt(1, 3) = 1
    Debug.Assert ModAlt(0, 3) = 0
    Debug.Assert ModAlt(-1, 3) = 2
    Debug.Assert ModAlt(-2, 3) = 1
    Debug.Assert ModAlt(-3, 3) = 0
    Debug.Assert ModAlt(-4, 3) = 2
    Debug.Assert ModAlt(-5, 3) = 1

    Debug.Assert ModAlt(5, -3) = -1
    Debug.Assert ModAlt(4, -3) = -2
    Debug.Assert ModAlt(3, -3) = 0
    Debug.Assert ModAlt(2, -3) = -1
    Debug.Assert ModAlt(1, -3) = -2
    Debug.Assert ModAlt(0, -3) = 0
    Debug.Assert ModAlt(-1, -3) = -1
    Debug.Assert ModAlt(-2, -3) = -2
    Debug.Assert ModAlt(-3, -3) = 0
    Debug.Assert ModAlt(-4, -3) = -1
    Debug.Assert ModAlt(-5, -3) = -2

    Debug.Assert ModAlt(2.5, 1.5) = 1
    Debug.Assert ModAlt(2, 1.5) = 0.5
    Debug.Assert ModAlt(1.5, 1.5) = 0
    Debug.Assert ModAlt(1, 1.5) = 1
    Debug.Assert ModAlt(0.5, 1.5) = 0.5
    Debug.Assert ModAlt(0, 1.5) = 0
    Debug.Assert ModAlt(-0.5, 1.5) = 1
    Debug.Assert ModAlt(-1, 1.5) = 0.5
    Debug.Assert ModAlt(-1.5, 1.5) = 0
    Debug.Assert ModAlt(-2, 1.5) = 1
    Debug.Assert ModAlt(-2.5, 1.5) = 0.5

    Debug.Assert IsNull(ModAlt(Null, 3))
    Debug.Assert IsNull(ModAlt("Joe", 3))
    Debug.Assert IsNull(ModAlt(3, Null))
    Debug.Assert IsNull(ModAlt(3, "Joe"))

End Function