Nested generic procedures in Ada

main.adb

procedure Main is
   generic
      type A_Type is private;
   procedure Outer (A : A_Type);

   procedure Outer (A : A_Type) is
      generic
         type B_Type is private;
      procedure Inner (A : A_Type; B : B_Type);

      procedure Inner (A : A_Type; B : B_Type) is
      begin
        null;
      end Inner;

      procedure Integer_Inner is new Inner (Integer);
   begin
      Integer_Inner (A, 2);
   end Outer;

   procedure Integer_Outer is new Outer (Integer);
begin
   Integer_Outer (1);
end Main;