5 How to use Ada 2005 OO?

from http://en.wikibooks.org/wiki/Ada_Programming/Object_Orientation

package X is 
   type Object is tagged null record; 
 
   procedure do (This: in Object; That: in Boolean); 
end X; 
 
with X; 
procedure Main is 
   Obj : X.Object; 
begin 
   Obj.do (That => True); 
end Main;