- From: Luc Moreau <l.moreau@ecs.soton.ac.uk>
- Date: Mon, 03 Sep 2012 14:52:24 +0100
- To: public-prov-wg@w3.org
Hi Stian, Re-reading the prov-constraints document, I think I disagree with one of your suggestions. On 06/08/12 16:37, Provenance Working Group Issue Tracker wrote: > PROV-ISSUE-471 (wrong-wasAttributedTo-constraints): wasAttributedTo constraints not sensical [prov-dm-constraints] > > http://www.w3.org/2011/prov/track/issues/471 > > Raised by: Stian Soiland-Reyes > On product: prov-dm-constraints > > I find the wasAttributedTo constraint 48 wrong > > >From Stian's review http://lists.w3.org/Archives/Public/public-prov-wg/2012Aug/0021.html > > http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-constraints-20120723/prov-constraints.html#wasAttributedTo-ordering_text > >> An entity that was attributed to an agent must have some overlap with the agent. > Why?? > > >> The agent is required to exist before the entity invalidation. > I don't agree with that. First of all, why has the attribution need to > have anything to do with the invalidation of an entity? If you > contribute to an entity, all of that has to happen *before* the entity > is generated. It does not matter what happens after that. > Why should this be *before* the entity exist? I believe one can use attribution as follows: wasAttributedTo(painting,Bob,[prov:type="ownership"]) I don't see why Bob should exist before the painting was created. So, to me, it makes sense that attribution relates the agent to the invalidation of the entity. >> Likewise, the entity generation must precede the agent destruction. > This also means it is not valid to attribute a book to an author if > the book was published after the author's death. (For instance The > GIrl with the Dragon Tattoo). > > By our inferences, it is only a requirement that the agent was > associated with an activity that eventually gave birth to the entity. > The agent is not required to be there till the end of the activity, > that sounds like an artificial constraint to me. Thus I would remove > constraint 48. > OK, I think we can relax this constraint as you suggest. Luc > What you can instead say that an agent's association with that > activity must precede an entity's generation, because otherwise he > can't be associated with its generating activity. This does not > directly follow from constraint 47 and Inference 15 > (attribution-inference), so we need a constraint to force the > generation to be after the *association* started, the first would then > follow. Association don't have time, unfortunately, but we can use > same reasoning as in constraint 47: > > IF wasAttributedTo(_at;e,ag,_attrs) and > wasGeneratedBy(genE;e,_a1,_t1,_attrs1) and > wasGeneratedBy(genAg;ag,_a1,_t1,_attrs1) THEN genAg precedes genE > > > We can't say anything about the entity's invalidation; attribution > relates to association with the generation, not invalidation. The > agent's invalidation after the start of the activity a1 (which does > not affect e) is covered by constraint 47+ inference 15. > > > > -- 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 Monday, 3 September 2012 13:53:03 UTC