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

Hi Paul,
Sorry about the mixup!

Constraint on wasGeneratedBy property (in PROV-DM document on Oct 10, 2011):
"If an assertion wasGeneratedBy(x,pe,q) or wasGeneratedBy(x,pe,q,t), then
generation of the thing denoted by x precedes the end of pe and follows the
beginning of pe."

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 Mon, Oct 10, 2011 at 2:29 PM, Paul Groth <p.t.groth@vu.nl> wrote:

> 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<sysbot%252Btracker@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<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.
>>
>>
>>
>>
>>