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Re: The Unordered control construct in DAML-S 0.7

From: Monika Solanki <monika@dmu.ac.uk>
Date: Mon, 21 Oct 2002 15:18:31 +0100
Message-ID: <3DB40CB7.6020400@dmu.ac.uk>
To: Paul Buhler <pbuhler@cs.cofc.edu>, www-ws <www-ws@w3.org>
Thanks for your Reply.

As mentioned by you:

The important thing to note is that in each of the possible execution 
orders, the sequence a;b and c;d are preserved.

As mentioned in the documnetation,

(Unordered a b) could result in the execution of a followed by b, or b
followed by a.

Which means that (Unordered X, Y) could result in the exceution of X, 
followed by Y or Y followed by X.

Hence we have two sets of execution ordering, ( I think)

{(a;b), (c;d)} or {(c;d), (a;b)}

Since the individual processes have been defined to be executed in 
sequence, I believe that their respective orders will be retained.

However as mentioned further in the documentation, these processes could 
be executed in any order and certain sets of execution have been 
defined. Therefore, I have a feeling that the orders a;b & c;d are not 
necessary to be preserved. This is the cause of my confusion.

I would apprecitae any further clarifications in this regards.

Thanks

Monika


Paul Buhler wrote:

> Hi Monika,
>
>  
>
> IMO, the DAML-S specification needs to be corrected to account for the 
> inconsistencies that you have pointed out. I suggest the following 
> fixes...
>
>  
>
> The line that currently reads "Z=(Unordered A B)" should read 
> "Z=(Unordered X Y)"
>
>  
>
> Likewise the duplicate entry (a;c;d;b) should be removed from the 
> list. The important thing to note is that in each of the possible 
> execution orders, the sequence a;b and c;d are preserved.
>
>  
>
> Regards,
>
>  
>
> Paul Buhler 
>
>     -----Original Message-----
>     From: www-ws-request@w3.org [mailto:www-ws-request@w3.org] On
>     Behalf Of Monika Solanki
>     Sent: Monday, October 21, 2002 4:21 AM
>     To: www-ws
>     Subject: The Unordered control construct in DAML-S 0.7
>
>      I am a bit confused over the control cnstruct " unordered" as
>     defined in DAML-S 0.7:
>
>     Let a, b, c, and d be atomic processes, and X, Y, and Z be
>     composite processes:
>     X = (Sequence a b)
>     Y = (Sequence c d)
>     Z = (Unordered A B)
>
>      do X & Y correspond to A & B respectively or am I missing something.
>
>     Z, then, translates to the following partial ordering:
>     {(a;b), (c;d)}
>     where ';' means \executes before", and the possible execution
>     sequences (total
>     orders) include
>     {(a;b;c;d), (a;c;b;d), (a;c;d;b), (a;c;d;b),
>     (c;d;a;b), (c;a;d;b), (c;a;b;d)}
>
>     are the repeition of execution sequence ordering a typo or
>     intentional.
>
>     Any comments will be helpful.
>
>     Thanks
>
>     Monika
>
>     -- 
>     >**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
>     Monika Solanki
>     De Montfort University
>     Software Technology Research Laboratory
>     Hawthorn building, H00.18
>     The Gateway.
>     Leicester LE1 9BH, UK
>
>     phone: +44 (0)116 250 6170 intern: 6170
>     email: monika@dmu.ac.uk <mailto:monika@dmu.ac.uk>
>     web: http://www.cse.dmu.ac.uk/~monika/
>     <http://www.cse.dmu.ac.uk/%7Emonika/>
>     >**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
>

-- 
 >**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
Monika Solanki
De Montfort University
Software Technology Research Laboratory
Hawthorn building, H00.18
The Gateway.
Leicester LE1 9BH, UK

phone: +44 (0)116 250 6170 intern: 6170
email: monika@dmu.ac.uk <mailto:monika@dmu.ac.uk>
web: http://www.cse.dmu.ac.uk/~monika/ 
<http://www.cse.dmu.ac.uk/%7Emonika/>
 >**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
Received on Monday, 21 October 2002 10:46:04 GMT

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