question on generics in class type declarations

[Neal Gafter]

I would like to have the possibility to introduce named types that
are

not type parameters of the parameterized class. For example:

class A<T extends B<U super T>> {
private U value;

}

I don't see why this shouldn't be allowed.

You'd write it this way:

class A<U, T extends U&B<U>> {
private U value;
}

It doesn't make any sense to me that you don't want U to be a parameter
of A.