[Odrl-version2] RE: ODRL-Version2 Digest, Vol 17, Issue 7

[Renato Iannella]

On 15 Jun 2006, at 00:11, Vicky Weissman wrote:

> Are the following 2 agreements the same?  If not, what is the
> difference (in English)?

They are not the same. The "c" Constraint applies to different parts  
of the expression.
In the first case, the "c" Constraint applies to the Duty, and the  
second case, the "c" Constraint
applies to the Permission.

So, assuming "c" is "before 2006-06-30" and "d" is "pay $EU5", then  
the first agreement says that:
   "Alice can Download Asset F if she pays $EU5 before 2006-06-30"

The second agreement would then say that:
   "Alice can Download Asset F before 2006-06-30 if she pays $EU5"

So, in the first agreement, Alice cannot do anything unless she pays  
$EU5 before 2006-06-30.
If she does pay $EU5 before 2006-06-30, then she can Download Asset F  
(at any time now or in the future).

So, in the second agreement, Alice cannot do anything unless she pays  
$EU5.
If she does pay $EU5, then she can Download Asset F before  
2006-06-30. If it is after that date, then she cannot download it,  
even if she has paid.


Is that a bit clearer?


> -------------------
> If we set the Boolean Duty.Relax=True, then that means the user is  
> obligated
> to fulfill the duty sometime (anytime!) in the future.  So we can't  
> use
> duties to obligate a user to do something at a certain time after  
> the right
> has been exercised (e.g., unlocking a resource within 48 hours of  
> acquiring
> the lock). Yes?
> ------------------

Correct, "relax" really means "relaxed" ;-)
Perhaps we need a constraint on that as well ?


Cheers

Renato Iannella
ODRL Initiative
http://odrl.net