- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Thu, 23 Feb 2012 13:59:53 +0000
- To: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
- CC: public-prov-wg@w3.org
Hi Khalid, I think the OWL-RL requirement that we cannot have a union in the domain of a property forces us to define a class for this union, but it is the very presence of this new class that allows us to express descriptions that are not aligned with the DM. Luc On 02/23/2012 01:09 PM, Khalid Belhajjame wrote: > > Hi Luc, > > I think your approach works, I don't see any issue for the moment. > Perhaps the only downside, which I don't think is that problematic, is > that we need to add extra sub-properties that (re)define the > properties defined at the level of the class that we cannot > instanciate, e.g., provs:entity which has as a domain > provs:EntityInvolvement, need to be redefined at the level of the > descendent classes that can be instanciated, e.g., prov:usedEntity for > prov:Usage. > > Thanks, khalid > > > On 23/02/2012 12:41, Luc Moreau wrote: >> Hi Khalid, >> >> Just trying to expand on this idea: >> >> :a1 a prov:Activity >> prov:used :e1 >> prov:usage [a Usage >> prov:usedEntity :e1 >> prov:usedTime t] >> >> >> Then, in prov-s (s for structure) >> >> >> prov:usedEntity subPropertyOf provs:entity >> prov:Usage subclassOf provs:EntityInvolvement >> prov:usedTime subRelationOf provs:hadTemporalExtent >> provs:entity domain: provs:EntityInvolvement >> range prov:Entity >> >> prov:usage subrelationOf provs:qualified >> provs:qualified domain: provs:Element >> range: provs:Involvement >> prov:Activity subclassOf provs:Element >> prov:Entity subclassOf provs:Element >> >> All the patterns are preserved. The concern about Involvement not >> being abstract has disappeared. In prov, you can't express instance >> of involvement, its' only in provs you can. >> >> Thoughts? >> >> Luc >> >> On 02/23/2012 11:52 AM, Khalid Belhajjame wrote: >>> On 23/02/2012 11:44, Luc Moreau wrote: >>>> Hi Khalid, >>>> >>>> Can the structure and vocabulary be in separate ontologies? >>>> This would allow the vocabulary to be kept as simple as possible, >>>> as close to the data model as possible. >>>> I don't think it would be a requirement for the structure-part to >>>> be OWL-RL compatible. >>> >>> I haven't thought about it hard, but I guess one of the issue we may >>> need to solve in that case is the properties that are common to the >>> sub-classes and defined at the level of the "abstract" class. For >>> example, EntityInvolvement has the property "entity" that is used to >>> specify the involved entity. If we opt for the solution you are >>> suggesting, then we will need to define such property for every >>> descendent class that can be instantiated. >>> >>> Khalid >>>> Thoughts? >>>> >>>> Luc >>>> >>>> On 02/23/2012 10:59 AM, Khalid Belhajjame wrote: >>>>> >>>>> In the prov-o ontology, the involvement class is used as a mean >>>>> for giving a structure to the ontology. There are different types >>>>> of involvement, e.g., Usage, Generation and Derivation. However, >>>>> as it is, the ontology allows specifying an instance of >>>>> Involvement that is not an instance of any of its sub-classes. >>>>> That should not be allowed. >>>>> >>>>> In OWL, the notion of abstract class does not exist, however, one >>>>> thing that can be done to avoid the above issue is to ass a >>>>> constraint specifying that Involvement is equivalent to the class >>>>> constructed by unionining its sub-class. While this solution is >>>>> plausible, I am not sure if this constraint is OWL-RL compatible. >>>>> I suspect so, but we need a confirmation. >>>>> >>>>> The same problem occurs in other cases in the ontology where the >>>>> classes have been introduced for shaping the structure of the >>>>> ontology, for example Element, ActivityInvolvement, >>>>> EntityInvolvement and AgentInvolvement. >>>>> >>>>> khalid >>>>> >>>> >>> >> > -- 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 Thursday, 23 February 2012 14:00:21 UTC