type Region = (Float,Float) -> Bool

unitcircle :: Region
unitcircle _ = True

scale :: Float -> Region -> Region
scale s r (x,y) = r (x*s,y*s)

union :: Region -> Region -> Region
union r1 r2 p = r1 p || r2 p

example = union (scale 2.0 unitcircle) unitcircle