Reflect point about the x axis
reflectPointXAxis :: (Num a) => Point a -> Point a
reflectPointXAxis (P x y) =
    P x (-y)

reflectPointXAxis :: (Num a) => Point a -> Point a
reflectPointXAxis (P x y) =
    P x (-y)
reflectPointXAxis (P x y) =
    P x (-y)