The compiler can't "see" an inner class

[Emmanuelle via Digitalmars-d-learn]

Hello! See snippet:

---
interface AST
{
    static interface Expr : AST
    {
        final static class Name : Expr
        {
            override void accept(AST.Visitor v) { 
v.visitName(this); }
        }
    }
    final static class Visitor
    {
        void visitName(AST.Expr.Name name);
    }

    void accept(AST.Visitor v);
}
---

If you try to compile that, dmd v2.088.0 complains:

---
Error: no property Name for type onlineapp.AST.Expr
---

How come? It's defined right there. I would really like some 
pointers on this, thanks!