Re: nested transactions

Is there going to be a way to use transactions inside transactions of 
transactions?
In other words:
   BEGIN;   BEGIN;   BEGIN;   BEGIN;
   COMMIT;   COMMIT;   COMMIT;   COMMIT;

Is there a way to have some sort of recursive solution with every 
transaction but the first one being a child transaction?
Is there a way to implement that without too much extra effort?
I just curious how that could be done.
   Hans