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Re: PROV-ISSUE-122: Constraint on wasGeneratedBy (PROV-DM and PROV-OM) [Conceptual Model]

From: Paul Groth <p.t.groth@vu.nl>
Date: Mon, 10 Oct 2011 20:29:58 +0200
Message-ID: <4E9339A6.5030808@vu.nl>
To: Satya Sahoo <satya.sahoo@case.edu>
CC: Provenance Working Group WG <public-prov-wg@w3.org>
Hi Satya,

Maybe I'm missing something but is the issue just the existence of this 
constraint?

Otherwise, the issue i just a repeat of the constraint.

Thanks for the clarification.

Paul

Satya Sahoo wrote:
> Hi all,
> There is an issue with the second constraint on wasGeneratedBy, hence I
> am combining this with the first constraint on wasGeneratedBy.
>
> Constraint (in PEOV-DM document on Oct 10, 2011):
> "An entity e may be generated before the end of pe, for example a
> manufacturing PE can generate multiple entities before terminating."
>
> Issue: An entity e may be generated before the end of pe, for example a
> manufacturing PE can generate multiple entities before terminating.
>
> Thanks.
>
> Best,
> Satya
>
> On Sun, Oct 9, 2011 at 7:36 PM, Provenance Working Group Issue Tracker
> <sysbot+tracker@w3.org <mailto:sysbot%2Btracker@w3.org>> wrote:
>
>
>     PROV-ISSUE-122: Constraint on wasGeneratedBy (PROV-DM and PROV-OM)
>     [Conceptual Model]
>
>     http://www.w3.org/2011/prov/track/issues/122
>
>     Raised by: Satya Sahoo
>     On product: Conceptual Model
>
>     The following constraint is defined on wasGeneratedBy in the PROV-DM
>     document (as on Oct 9, 2011):
>     "Given a process execution pe, entity e, role r, and optional time
>     t, if the assertion wasGeneratedBy(e,pe,r) or
>     wasGeneratedBy(e,pe,r,t) holds, the values of some of e's attributes
>     are determined by the activity denoted by pe and the entities used
>     by pe. Only some (possibly none) of the attributes values may be
>     determined since, in an open world, not all used entities may have
>     been asserted."
>
>     Issue: This constraint seems to be self-contradictory due to the two
>     phrases "...the values of some of e's attributes are determined by
>     the activity denoted by pe..." and "Only some (possibly none) of the
>     attributes values may be determined...".
>
>     In addition, this constraint cannot be enforced, since which
>     attributes will be determined are not specified and given the use of
>     open world assumption, there be always some attribute that is not
>     currently associated with the entity.
>
>     Overall, this constraint does not help either in inferring new
>     knowledge from existing information or allow "validation/checking"
>     of existing knowledge - which are the standard uses of
>     rules/constraints. Hence, the suggestion is to remove this constraint.
>
>
>
>
Received on Monday, 10 October 2011 18:30:37 GMT

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