- From: Birte Glimm <birte.glimm@comlab.ox.ac.uk>
- Date: Fri, 12 Mar 2010 00:31:47 +0000
- To: Chimezie Ogbuji <ogbujic@ccf.org>
- Cc: Ivan Herman <ivan@w3.org>, SPARQL Working Group WG <public-rdf-dawg@w3.org>, Axel Polleres <axel.polleres@deri.org>, Sandro Hawke <sandro@w3.org>
On 11 March 2010 17:30, Chimezie Ogbuji <ogbujic@ccf.org> wrote: > Comments below > > On 3/10/10 9:35 AM, "Birte Glimm" <birte.glimm@comlab.ox.ac.uk> wrote: >> Yes, that's what I mean. As I understand it SG or sk(SG) is the graph >> you get from the triples and it knows nothing about the rule set. We >> would have to specify a vocabulary that is the union of the vocabulary >> of SG/sk(SG) and the vocabulary of the import closure of the >> referenced rule sets. That's not difficult to do, we should just add >> it. > > Do we even need this condition for RIF Simple entailment? The vocabulary of > the generalized RDF graphs entailed by the combination (strongly, safe RIF > Core document,sk(SG)) 'include' the vocabulary of SG and the corresponding > RDF names in the RIF document (this also includes its import closure). Is > there an example that demonstrates needing anything more than requiring that > the RDF triples sk(P(BGP)) are ground and RIF-Simple entailed by the > combination? When you don't need C2 because you'll anyway only entail a finite number of triples (modulo bnode identifier), then that's not necessary. I guess strongly safe gives you just that. As soon as you add C2, you want to have a vocabulary does cover enough so that you don't exclude triples that are entailed and that you would like to keep. Birte > I have updated the Simple RIF Core entailment regime with a paragraph that > briefly discusses this. Going back to your example below > > .. if we have SG: > ex:a a ex:b . > rif-rdf:usesRuleset ex:rules.rif . > > with ex:rules.rif: > ex:b(x) -> ex:c(x) > > and query: > > SELECT ?x WHERE { ?x a ex:c } > > Then I (too) would expect to get ?x/ex:a > > In this case sk(P(BGP)) is the same as P(BGP): > > ex:a a ex:c > > And the entailed, generalized graph EG would be (a proper superset of SG): > > ex:a a ex:b . > ex:a a ex:c > > In which case P(BGP) is a subgraph of EG. So, there is no need to > explicitly restrict the bound names. > > > -- Chime > > > =================================== > > P Please consider the environment before printing this e-mail > > Cleveland Clinic is ranked one of the top hospitals > in America by U.S.News & World Report (2009). > Visit us online at http://www.clevelandclinic.org for > a complete listing of our services, staff and > locations. > > > Confidentiality Note: This message is intended for use > only by the individual or entity to which it is addressed > and may contain information that is privileged, > confidential, and exempt from disclosure under applicable > law. If the reader of this message is not the intended > recipient or the employee or agent responsible for > delivering the message to the intended recipient, you are > hereby notified that any dissemination, distribution or > copying of this communication is strictly prohibited. If > you have received this communication in error, please > contact the sender immediately and destroy the material in > its entirety, whether electronic or hard copy. Thank you. > > -- Dr. Birte Glimm, Room 306 Computing Laboratory Parks Road Oxford OX1 3QD United Kingdom +44 (0)1865 283529
Received on Friday, 12 March 2010 00:32:27 UTC