[nem-en] Can inherited method be an inteface implementation?

[Vladimir Reshetnikov]

class Base[T]
{
    public Foo(x : T) : void {}
}

interface IFace
{
    Foo(x : int) : void;
}

class Derived : Base[int], IFace { } /* error : unimplemented
interface method IFace.Foo(x : int) : void (in Derived type) */

Why this does not compile? In C#, it is OK.