Re: PROV-ISSUE-454 (key across relations/objectss): can the same identifier be used for different relations objects [prov-dm-constraints]

I added the remark here:

http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#entity-activity-disjoint

feel free to rephrase if you're not happy with this.

Tom


2012/7/19 Luc Moreau <l.moreau@ecs.soton.ac.uk>

>
> Hi Tom,
>
> Do you want to add a remark somewhere about this.
> It's indeed worth saying (maybe after the entity/activity disjointness)
>
> Luc
>
>
> On 07/19/2012 11:03 AM, Tom De Nies wrote:
>
> This (partly) addresses my concern I just formulated a few minutes ago.
>
> The place in the document is fine where it is now for me. I'd either put
> it here, or right behind the key-object constraint 25.
> I would, however, rephrase it to match the other constraints in form:
>
> IF entity(id1,_attrs1) and activity(id2,_t1,_t2,_attrs2) THEN id1 =/= id2
>
> Then my only concern that remains is that we implicitly assume that when
> agent(a1) and entity(a1) are asserted, they refer to the same thing. (Which
> is fine by me, but I do think we should mention it somewhere.)
>
> - Tom
>
>
> 2012/7/19 Luc Moreau <l.moreau@ecs.soton.ac.uk>
>
>>
>> as I was writing disjointness constraints, I also added activity/entity
>> disjointness constraint.
>> I am not sure it is at the right place.
>>
>>
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#entity-activity-disjoint
>>
>>
>> Luc
>>
>>
>>
>> On 07/19/2012 10:43 AM, Luc Moreau wrote:
>>
>> Hi all,
>>
>> I tried to formulate a constraint to express this.
>>
>>
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#key-relation2
>>
>> Thoughts?
>>
>> Luc
>> On 07/18/2012 10:57 AM, James Cheney wrote:
>>
>> HI,
>>
>>  Again, I don't see the need for an explicit issue about this.
>>
>>  There is currently no constraint enforcing disjointness among different
>> kinds of things/relations.  I see no particular reason to add one (and make
>> implementation harder), unless there is clear consensus that violating such
>> constraints is always nonsensical (and that this isn't detected by other
>> constraints).
>>
>>  We (I thought) want to allow for the possibility that something is both
>> an agent and an entity, or both an agent or an activity, or other
>> combinations.  One could then state that something influences, generates,
>> uses itself etc., but this will just violate ordering constraints that we
>> already have.
>>
>>  I agree it seems nonsensical to allow overlap between different
>> relations, and if so then someone needs to write constraints that do this.
>>
>>  Constraints of the form "if hyp1 .... hypn then FALSE" (i.e., a given
>> conjunctive pattern is impossible" are straightforward to handle: we just
>> handle all the other inferences and constraints first, then check that the
>> normal form does not have any of the forbidden patterns.  (The
>> irreflexivity and asymmetry inferences for specialization already do this
>> implicitly.)
>>
>>  --James
>>
>>  On Jul 18, 2012, at 10:39 AM, Tom De Nies wrote:
>>
>>  The only problem I see with allowing it, is when using influencedBy.
>>
>> With influence you'd be allowed to assert this:
>>
>> agent(a1)
>> activity(a1)
>> influencedBy(a1,a1)
>>
>> - Tom
>>
>>  2012/7/18 Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
>>
>>> PROV-ISSUE-454 (key across relations/objectss): can the  same identifier
>>> be used for  different relations objects [prov-dm-constraints]
>>>
>>> http://www.w3.org/2011/prov/track/issues/454
>>>
>>> Raised by: Luc Moreau
>>> On product: prov-dm-constraints
>>>
>>>
>>> We have the following two uniqueness constraints.
>>>
>>>
>>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#key-object
>>>
>>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#key-relation
>>>
>>> It is not clear to me if
>>>
>>> entity(e123)
>>> agent(e123)
>>>
>>> are acceptable. (To me, they should be, since we don't state the set of
>>> agents to be disjoint from any other set)
>>>
>>> Likewise, can we write
>>>
>>> used(event1234,a1,e1,attrs1)
>>> and
>>> wasGeneratedBy(event1234,e2,a2,attrs2)
>>>
>>> Probably not.
>>> Note: if we allow the two above, then I am not sure that strict ordering
>>> is wise in ordering constraints.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>> The University of Edinburgh is a charitable body, registered in
>> Scotland, with registration number SC005336.
>>
>>
>> --
>> 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
>>
>>
>>
>>
>> --
>> 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
>>
>>
>>
>>
>
> --
> 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
>
>
>
>