not null access procedure (was: Re: Dynamic String)

[Anonymous Coward <bogus_addy@bogus_domain.net>]

In article <1130875772.717413.45520@g14g2000cwa.googlegroups.com>, Matthew Heaney wrote:
> 
> Ada 2005 will indeed include a standard container library.  You can
> find the latest AI-302 draft (released just a couple of days ago)
> here:
> 
> http://www.ada-auth.org/cgi-bin/cvsweb.cgi/AIs/AI-20302.TXT?rev=1.23

I noticed some syntax in the package specification of that link above,
which is unfamiliar to me:

   procedure Update_Element
     (Container : in out Vector;
      Index     : in     Index_Type;
      Process   : not null access procedure (Element : in out Element_Type));

What is meant by this "not null"?  Is this available in ADA95, or new
to ADA05?

I also had a more general question with access procedures.  Does an
access procedure still have scope in the package it is defined in?
Will it be able to access other subprograms and variables that it
normally would, when it is executed by the container package,
considering the container package has no visibility into its user?