-- foo.ads
with Foobar;
package Foo is
   package Bar renames Foobar;
end Foo;

-- foobar.adb
with Ada.Text_IO;

package body Foobar is
   procedure Blarg is
   begin
      Ada.Text_IO.Put_Line ("Blarg");
   end Blarg;
end Foobar;

-- foobar.ads
package Foobar is
   procedure Blarg;
end Foobar;

-- main.adb
with Foo;

procedure Main is
begin
   Foo.Bar.Blarg;
end Main;