// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// @assertion
/// NORM(X extends T) =
///  let S be NORM(T)
///  if S is Never then Never
///  else X extends T
///
/// @description Checks that if NORM(T) is NORM(X extends T)
///
/// @author sgrekhov@unipro.ru

// Requirements=nnbd-strong
class T {}
class T1 extends T {}
class T2 extends T {}
class A<X> {}
class B<X extends T> implements A<X> {}

class C extends B<T1> implements A<T1> {}

main() {
  new C();
}