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Re: PROV-ISSUE-471 (wrong-wasAttributedTo-constraints): wasAttributedTo constraints not sensical [prov-dm-constraints]

From: Luc Moreau <l.moreau@ecs.soton.ac.uk>
Date: Tue, 04 Sep 2012 12:33:19 +0100
Message-ID: <EMEW3|5fa830fbfd771f0ddc55d3b02264b58eo83CXL08l.moreau|ecs.soton.ac.uk|5045E6FF.5070908@ecs.soton.ac.uk>
To: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
CC: public-prov-wg@w3.org

Hi Stian,

Figure 6b updated to reflect wasAttributed_ordering, with your stricter 
ordering constraint.

Luc

On 03/09/12 17:09, Stian Soiland-Reyes wrote:
> On Mon, Sep 3, 2012 at 2:53 PM, Luc Moreau <l.moreau@ecs.soton.ac.uk> wrote:
>>
>> I suggest the constraints becomes as follows:
>>
>> IF wasAttributedTo(_at;e,ag,_attrs) and
>> wasInvalidatedBy(invE;e,_a1,_t1,_attrs1) and
>> wasGeneratedBy(genAg;ag,_a1,_t1,_attrs1) THEN genAg precedes invE
> Although this laxer constraint would still be 'true', I wonder then
> about the point of this:
>
>> Inference 13 (attribution-inference)
>> IF wasAttributedTo(_att; e,ag,_attrs) THEN there exist a, _t, _gen, _assoc, _pl, such that wasGeneratedBy(_gen; e,a,_t,[]) and wasAssociatedWith(_assoc; a,ag,_pl,[]).
> If I assume for the argument that wasAttributedTo also covers any kind
> of ownership (which as you know I don't approve of ;) ), then I
> struggle with the above inference, as this forces the agent to also be
> involved with the *generation* of that entity. If I buy a car, then
> yes, I might be involved in the "purchasing" activity, which you can
> say is what generated the StiansCar entity. (which lives for as long
> as it has the characteristic of being owned by me -  note that this
> sounds more like attributes and entity characterisation) - but is this
> true for any kind of ownership? If I inherit a massive castle, or I
> have received in the mailbox (in a house I have just moved in to) a
> 2013 calendar from a local shop, am I then 'attributed to' the castle
> or the calendar, and required to be associated with the activity that
> made me the owner?
>
>
> Should it then not a requirement be for the agent to be involved with
> the activity before the entity was generated? Your proposed constraint
> (as quoted above) would allow the agent to come to life just before
> the invalidation of the entity, get a brief ownership (duration of
> which we don't know), and then let the entity invalidate.  It is OK
> with the wasAssociatedWith-ordering rule as long as the activity that
> generated the entity is still running at this point, for instance that
> the factory is still making cars or the postman still doing his
> deliveries.
>
> This sounds a bit odd for me. It should be one way or the other.  The
> time ordering constraints should cover, ideally, exactly what is
> required, not allow various scenarios we do not intend to be legal.
>
> If the ownership is true for the whole lifetime of the entity (which I
> would presume!), then that is an attribute that I would see in the
> entity, not as a separate statement. If it is still to be said as a
> statement, then we need boundary conditions on both sides, just like
> we say attributes are valid all the way from the generation till
> invalidation.
>
>
> My proposal is to keep the current definition:
>
>> Constraint 50 (wasAttributedTo-ordering)
>> IF wasAttributedTo(_at; e,ag,_attrs) and wasGeneratedBy(gen1; ag,_a1,_t1,_attrs1) and wasGeneratedBy(gen2; e,_a2,_t2,_attrs2) THEN gen1 precedes gen2.
>> IF wasAttributedTo(_at; e,ag,_attrs) and wasStartedBy(start; ag,_e3,_a3,_t3,_attrs3) and wasGeneratedBy(gen; e,_a4,_t4,_attrs4) THEN start precedes gen.
> (Note: There are two rules, depending on the agent being an entity or
> an activity. We can't time-order non-entity, non-activity agents).
>
>
> This says that the agent must be involved in the generation of the
> entity. We do not have time stamps on association, but the intention
> is that he was associated before entity generation. This must be true
> - from the above - also for the case of ownership.
>
> The agent is not required to be involved with its invalidation, but we
> know that the the invalidation must be after his generation, because
> of the combination of constraint generation-precedes-invalidation and
> wasAttributedTo-ordering.
>
>
> --
> Stian Soiland-Reyes, myGrid team
> School of Computer Science
> The University of Manchester

-- 
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
Received on Tuesday, 4 September 2012 11:33:57 GMT

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