RE: [SKOS, SPARQL, ALL] Closure and SPARQL

Ah, then I rest my case.
I just got the impression that this was not possible on the same graph.
As Brain stated:

"I earlier suggested that SPARQL does not have to support transitive closure because the graph can do it.  There can be an inferencing graph which computes the transitive closure of skos:narrower.  If you query that graph you query the transitive closure relationship.  If you query the ground graph you get the direct, well at least directly asserted, relationship."

I got the impression that 2 graphs would be needed if direct and indirect relations had to be taken into account. But if I understand correctly, the transitive nature of subPropertyOf and subClassOf is being taken into account, but the owl:transitiveProperty is not. I got the impression that transitivity was not taken into account at all, not even for subPropertyOf and subClassOf, and queries were only possible on direct assertions, which was my main concern. 

Case closed, I guess.

Christoffel


This email and its attachment(s) is confidential and intended solely for the use of the individual to whom it is addressed, and not intended to be further distributed without explicit prior approval of the sender. Any views or opinions presented are solely those of the author and do not necessarily represent those of Language & Computing, Inc. unless explicitly indicated. If you are not the intended recipient, be advised that you have received this email in error and that any use, dissemination, forwarding, printing, or copying of this email is strictly prohibited.

 

 


> -----Original Message-----
> From: Enrico Franconi [mailto:franconi@inf.unibz.it]
> Sent: maandag 12 december 2005 15:39
> To: Christoffel Dhaen
> Cc: McBride, Brian; David Wood; Pat Hayes; Christopher Welty; public-swbp-
> wg@w3.org
> Subject: Re: [SKOS, SPARQL, ALL] Closure and SPARQL
> 
> On 12 Dec 2005, at 15:23, Christoffel Dhaen wrote:
> > HasPet subPropertyOf Likes
> > Person subClassOf Animal
> > Woman subClassOf Person
> > OldLady subClassOf Woman
> > OldLady HasPet Cat
> > Cat subClassOf Animal
> >
> > A query
> > (X subClass Person) AND (X Likes Animal)
> > gives the answer
> > {X= OldLady}
> >
> > This takes the class-hierachy into account, as wel as the property
> > hierachy.
> >
> > Unless I have I missed this somewhere, according to the
> > specifications, the query on this graph would not give this result
> > and the resultset would be empty.
> >
> > I would say "simple RDf entailment" and "RDF entailment" entailment
> > as you point out in 2) should be possible on the same graph, but I
> > got the impression that this is not possible.
> > 1) can be resolved by doing a minus between the entailment and the
> > simple entailment results.
> 
> According to the current state of discussion in the DAWG, the use of
> "simple RDF entailment" and "RDF entailment" is possible and it would
> actually capture what you want as you point out.
> 
> cheers
> --e.
> 
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.371 / Virus Database: 267.13.13/197 - Release Date: 9/12/2005
> 

-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.371 / Virus Database: 267.13.13/197 - Release Date: 9/12/2005

Received on Monday, 12 December 2005 15:16:52 UTC