pSub :: (Num a) => Point a -> Point a -> Point a
pSub (Point x1 y1) (Point x2 y2) = Point (x1 - x2) (y1 - y2)
pSub :: (Num a) => Point a -> Point a -> Point a
pSub (Point x1 y1) (Point x2 y2) = Point (x1 - x2) (y1 - y2)
pSub (Point x1 y1) (Point x2 y2) = Point (x1 - x2) (y1 - y2)