// CS0425: The constraints for type parameter `V' of method `Foo<T>.Test<V>()' must match the constraints for type parameter `U' of interface method `IFoo<T>.Test<U>()'. Consider using an explicit interface implementation instead // Line: 13 interface IFoo<T> { void Test<U> () where U : T; } class Foo<T> : IFoo<T> { public void Test<V> () where V :X { } } class X { static void Main () { } }