- From: Adrian Walker <adrianw@snet.net>
- Date: Mon, 05 Dec 2005 21:10:44 -0500
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: semantic-web@w3.org
Peter -- A thought about "those were not the results I expected" and SPARQL... One of the bad things about the various implementations of classical SQL is that they have divergent semantics -- that is, they can produce different results given the same query and data. For combined use of OWL + RDF + SPARQL + SWRL it seems even more important that there should be a simple, accessible model theory (analogous to [1]) that implementers of the combined languages can adhere to with a reasonable amount of effort. (This is argued in more detail in [2]). Does such an animal exist, or is there perhaps work in that direction? Thanks in advance for pointers. -- Adrian [1] Backchain Iteration: Towards a Practical Inference Method that is Simple Enough to be Proved Terminating, Sound and Complete, A. Walker. Journal of Automated Reasoning, 11:1-22. [2] Understandability and Semantic Interoperability of Diverse Rules Systems www.w3.org/2004/12/rules-ws/paper/19 (With apologies if this note has some html in it. My email program is a bit independent about outgoing format) INTERNET BUSINESS LOGIC (R) Online at www.reengineeringllc.com Shared, community use is FREE. Adrian Walker Reengineering PO Box 1412 Bristol CT 06011-1412 USA Phone: USA 860 583 9677 Cell: USA 860 830 2085 Fax: USA 860 314 1029 At 12:48 PM 12/5/2005 -0500, you wrote: >Hmm, adding SPARQL into the mix is indeed adding a significant new piece >of the >puzzle. The SPARQL spec is still in flux, I believe, and some readings of it >may support the behaviour you are experiencing. > >peter > > >From: Andrea Splendiani <andrea@pasteur.fr> >Subject: Re: Question about SWRL semantics >Date: Mon, 5 Dec 2005 18:41:14 +0100 > > > Ok, > > I just forgot one point. > > I was testing it querying through SPARQL, > > I guess anyway SPARQL should se an "inffered set of relations", o that > > is not an issue. Isn't it ? > > > > The semantics you describe is the one I expected. > > > > best, > > Andrea Splendiani > > > > Il giorno 05/dic/05, alle 18:31, Peter F. Patel-Schneider ha scritto: > > > > > > > > From: Andrea Splendiani <andrea@pasteur.fr> > > > Subject: Question about SWRL semantics > > > Date: Mon, 5 Dec 2005 18:15:14 +0100 > > > > > >> Hi, > > >> I['m] asking this here but feel free to redirect me to some more > > >> specific > > >> resources if it is the case. > > >> > > >> I was using SWRL rules in Protégé and I have noticed that SWRL does > > >> not > > >> "view" the relations that can be inferred from OWL. > > >> > > >> Is this a feature of SWRL semantics ? > > >> Is is just undefined and "implementation specific" ? > > >> Is it due to the inability of the reasoner (Pellet) to infer too much > > >> about instances ? > > >> > > >> best, > > >> Andrea Splendiani > > > > > > If you have a KB (however this is formed) that includes both SWRL > > > rules and OWL > > > axioms then a complete SWRL reasoner should "take note" of both the > > > rules and > > > the axioms, as specified in the SWRL documentation. > > > > > > So, for example, > > > > > > Class(Student Person) > > > Class(Rock Immobile) > > > Individual(John type(Student)) > > > Implies(Antecedent(Person(I-variable(x))) > > > Consequent(Rock(I-variable(x)))) > > > > > > entails > > > > > > Individual(John type(Immobile)) > > > > > > > > > I do not know why you are not obtaining the results you expect, but it > > > seems to > > > me that you are expecting the results that are provided by the SWRL > > > semantics. > > > > > > Peter F. Patel-Schneider > > > Bell Labs Research > > > > > > > > >
Received on Tuesday, 6 December 2005 02:11:05 UTC