@Inheritable
Point2D = Class {::[<: Self]x = Int; ::[<: Self]y = Int}
Point2D.
    norm self = self::x**2 + self::y**2 #OK

Point3D = Inherit Point2D, Additional := {z = Int}
Point3D.
    @Override
    norm self = self::x**2 + self::y**2 + self::z**2 #OK

C = Class()
C.
    method point: Point2D = point::x # ERR

p = Point3D.new {x = 1; y = 2; z = 3}
p::x # ERR
p.x  # ERR
p::z # ERR

rec = {
    ::[f] x = 1
}

f x = rec::x + x # OK
g x = rec::x + x  # ERR

unpack {x; y}: {.x = Int; .y = Int} = x + y

private = { x = 1; y = 2 }
public = { .x = 1; .y = 2 }

_ = unpack public # OK
_ = unpack private # ERR

unpack2 {x; y} = x + y

_ = unpack2 public # OK
_ = unpack2 private # ERR