type access Parent'Class

[Yukicanis <yukicanis@googlemail.com>]

Dear Group,

I'm new to Ada and currently playing around with its OOP features.
Now, I have the following source:

procedure Test is
  type Parent is tagged limited null record;
  type Parent_Access is access Parent'Class;
  A : access Parent'Class;
  B : Parent_Access;
  procedure Dyn_Disp(X : access Parent'Class) is
  begin
    A := X;
    B := X;
  end Dyn_Disp;
begin
  null;
end Test;

When I try to complie that with GNAT 4.6.1 I get the following error
message:

test.adb:9:10: expected type "Parent_Access" defined at line 3
test.adb:9:10: found type access to "Parent'Class" defined at line 6

which I don't really understand since type "Parent_Access" is type
access to Parent'Class, isn't it?

Thanks in advance.