inc :: Double -> Inc
inc d
    | d >= 0.0 && d < 0.33  = Subtract
    | d >= 0.33 && d < 0.66 = Same
    | otherwise             = Add
inc :: Double -> Inc
inc d
    | d >= 0.0 && d < 0.33  = Subtract
    | d >= 0.33 && d < 0.66 = Same
    | otherwise             = Add
inc d
    | d >= 0.0 && d < 0.33  = Subtract
    | d >= 0.33 && d < 0.66 = Same
    | otherwise             = Add