- From: Chimezie Ogbuji <ogbujic@ccf.org>
- Date: Thu, 09 Apr 2009 21:42:45 -0400
- To: "Bijan Parsia" <bparsia@cs.man.ac.uk>, "RDF Data Access Working Group" <public-rdf-dawg@w3.org>
On 4/8/09 11:44 AM, "Bijan Parsia" <bparsia@cs.man.ac.uk> wrote: > On 8 Apr 2009, at 16:01, Axel Polleres wrote: > [snip] > This seems to confuse several things: > > 1) the semantics of the BGP (not your 1 I think.) The semantics of the BGP would be an extension via an entailment regime ( RIF-RDF combinations of OWL DLP). The well-formed graphs are the ones that can be embedded in RIF documents. Model theory can be used to say what the answers should be (not how to get them). It would be nice if fully expressive OWL-DL (like the abstract syntax described in SPARQL-DL) were used to extend SPARQL at the same time we extend it for RIF "embeddings" > 2) what gets into the BGP (your 2) Arbitrary BGPs (but with no bnodes in queries, for a start). Or the abstract syntax described in SPARQL-DL, even. > 3) how one says what the semantics are (and what gets in) (not your 3) An OWL-DL model theory can be used to govern the semantics ( or the models of RIF documents embedded with OWL-DLP and RDF ). > For 2, I'm not quite sure how this differs from any other (named) > graph manipulation. Take two graphs (DATA and RULES). (I guess I'm > presuming an RDF syntax for the RULES in this example). The key > question is whether Answers(Query, DATA union RULES) is the same as > (Answers(Query, DATA) union Answers(Query, DATA)). > > For the case of RDF encoded rules, under the standard sparql > entailment regime, I believe these will be equal. Under, say, a RIF > entailment regime, they probably wouldn't be. A RIF/OWL entailment extension of SPARQL? > A) We need a way to name entailment regimes (either a fixed list, or > extensible) Some simple, URI-based registry of regimes with well-defined entailment relationships that are well-formed. We probably can't deal with Bnodes in every case. > B) We need to trigger entailment regimes in a query > (Lots of issues there, e.g., only for the whole query, or settable > on a graph by graph basis; or over sets of graphs, or their merge). Just for the query. > Is there anything else, conceptually speaking, in the idea of > Parameterized Inference per se? I can't think of anything else. ---------------------- Chimezie Thomas-Ogbuji Heart and Vascular Institute (Clinical Investigations) Cleveland Clinic (ogbujic@ccf.org) Ph.D. Student Case Western Reserve University (chimezie.thomas-ogbuji@case.edu) =================================== 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 (2008). 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.
Received on Friday, 10 April 2009 01:43:39 UTC