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

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 
> <mailto: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 <mailto: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  <tel:%2B44%2023%208059%204487>
>>     University of Southampton          fax:+44 23 8059 2865  <tel:%2B44%2023%208059%202865>
>>     Southampton SO17 1BJ               email:l.moreau@ecs.soton.ac.uk  <mailto:l.moreau@ecs.soton.ac.uk>
>>     United Kingdomhttp://www.ecs.soton.ac.uk/~lavm  <http://www.ecs.soton.ac.uk/%7Elavm>
>>
>>
>>
>
>     -- 
>     Professor Luc Moreau
>     Electronics and Computer Science   tel:+44 23 8059 4487  <tel:%2B44%2023%208059%204487>
>     University of Southampton          fax:+44 23 8059 2865  <tel:%2B44%2023%208059%202865>
>     Southampton SO17 1BJ               email:l.moreau@ecs.soton.ac.uk  <mailto:l.moreau@ecs.soton.ac.uk>
>     United Kingdomhttp://www.ecs.soton.ac.uk/~lavm  <http://www.ecs.soton.ac.uk/%7Elavm>
>
>
>
>

-- 
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