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Re: PROV-ISSUE-191: Section 5.3.1.2 (PROV-DM as on Nov 28) [prov-dm]

From: Satya Sahoo <satya.sahoo@case.edu>
Date: Thu, 8 Dec 2011 12:07:31 -0500
Message-ID: <CAOMwk6x7rAm3Ok3HyZWAHntjSciLSpTzupzKY-hO_TeQ0XqdUw@mail.gmail.com>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Cc: public-prov-wg@w3.org
Hi Luc,
Temporal is related to time. Event is a dimension distinct from time,
similar to space being distinct from time. Event in distributed systems
allows us to have a partial ordering between communications without the use
of a central time keeping facility.

Hence, it is important not to use event and time interchangeably since I
believe the original argument in DM for introduction of event was that we
do not want to define/include time. By using time and event
interchangeably, we no longer support that justification.

The easy option seems to be replace event ordering instead of temporal
ordering. But, there might be more issues involved.

Thanks.

Best,
Satya

On Thu, Dec 8, 2011 at 4:54 AM, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote:

> Hi Satya
>
> As indicated in my response to PROV-ISSUE-190, I don't understand what
> problem there is with the term temporal constraint.
>
> Luc
>
> On 12/07/2011 02:05 AM, Provenance Working Group Issue Tracker wrote:
>
>> PROV-ISSUE-191: Section 5.3.1.2 (PROV-DM as on Nov 28) [prov-dm]
>>
>> http://www.w3.org/2011/prov/**track/issues/191<http://www.w3.org/2011/prov/track/issues/191>
>>
>> Raised by: Satya Sahoo
>> On product: prov-dm
>>
>> Hi,
>> The following are my comments for Section 5.3.1.2 of the PROV-DM (as on
>> Nov 28):
>>
>> 5.3.1.2 Usage Record
>> 1. "For any entity, the following temporal constraint holds: the
>> generation of an entity always precedes any of its usages."
>>
>> Comment: This is not a temporal constraint, since it only enforces a
>> partial order between events.
>>
>> 2. "Given an activity record identified by a, an entity record identified
>> by e, a set of attribute-value pairs attrs, and optional time t, if
>> assertion used(a,e,attrs) or used(a,e,attrs,t) holds, then the following
>> temporal constraint holds: the usage of the entity represented by entity
>> record identified by e precedes the end of activity represented by record
>> identified by a and follows its start."
>>
>> Comment: Similar to previous constraint, this is an event ordering
>> constraint and not a temporal constraint. Especially for assertion
>> used(a,e,attrs) where there is not time value explicitly associated with
>> used.
>>
>> Thanks.
>>
>> Best,
>> Satya
>>
>>
>>
>>
>>
>
> --
> Professor Luc Moreau
> Electronics and Computer Science   tel:   +44 23 8059 4487
> University of Southampton          fax:   +44 23 8059 2865
> Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
> United Kingdom                     http://www.ecs.soton.ac.uk/~**lavm<http://www.ecs.soton.ac.uk/~lavm>
>
>
>
Received on Thursday, 8 December 2011 17:07:59 UTC

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