object Test extends App { trait A trait B extends A class C { type D trait E { type T >: B <: A; val x : T } // This is currently correctly disallowed // val y : (D with E)#T = y val y : D with E = y var sneak = { () => y.x } sneak = { () => new B { } } } class F extends C { trait G trait H { type T = G } type D = H def frob(arg : G) : G = arg frob(sneak()) } new F }