Why is `enum of enum of enum..` allowed?

Question

I cannot understand why this even compile. I've tried with different formats and they all seem to work..

why is it legal to have an enum of enum of enum of..?

interface I {

    enum E implements I {
        VAL;
    }

    class Test {
        I.E         f1 = I.E.VAL;
        I.E.E       f2 = I.E.VAL;
        I.E.E.E     f3 = I.E.VAL;
        I.E.E.E.E.E f4 = I.E.VAL;

        I.E v1 = I.E.VAL;
        I.E v2 = I.E.E.VAL;
        I.E v3 = I.E.E.E.E.E.E.VAL;
        I.E v4 = I.E.E.E.E.E.E.E.E.E.E.VAL;
    }
}

My IDE reports it compiles just fine, although I.E.E does not make sense to me.

Answer 1

Your I interface contains an enum type named E.

This type implements that same I interface, so it inherits everything that that interface contains.
This includes the E type itself.

In other words, I.E.E is accessing I.E as inherited by E from the outer I.