- From: Birte Glimm <birte.glimm@comlab.ox.ac.uk>
- Date: Fri, 27 Aug 2010 23:32:38 +0100
- To: "Polleres, Axel" <axel.polleres@deri.org>
- Cc: public-rdf-dawg@w3.org
On 27 August 2010 20:13, Polleres, Axel <axel.polleres@deri.org> wrote: > Yes, the second one was meant as D-entailment test case, and I expected both not to return any result. Because it is not well-formed RDF or because you think it is not entailed? Birte > Axel > > ----- Original Message ----- > From: b.glimm@googlemail.com <b.glimm@googlemail.com> > To: Polleres, Axel > Cc: SPARQL Working Group <public-rdf-dawg@w3.org> > Sent: Fri Aug 27 20:11:39 2010 > Subject: Re: Thinking out lout about some strange SPARQL entailment test cases... > > Sorry, I didn't comment on the second test case > >> Similarly: >> >> G: >> :s :p 1 >> >> Q: >> SELECT ?L >> WHERE { ?L a xsd:integer } > > I think that would need datatype awareness and RDFS does not support > the XSD schema datatypes (you would need D-Entailment or higher). Even > if we have > :s :p "1"^^xsd:integer. > a system unaware of xsd datatypes might read that triples, but it will > not necessarily infer > "1"^^xsd:integer a xsd:integer . > or even > "1"^^xsd:integer a xsd:short . > which is also true I guess. At least for OWL reasoners what counts > internally is the denoted data value and "1"xsd:short and > "1"xsd:integer is the same data vale with different lexical forms. Now > for OWL Direct Semantics that BGP is not legal, so your only hope > would be OWL with RDF-Based Semantics or some D-Entailment > implementation. > > Now, even with XSD awareness and not counting it as illegal RDF, the > answers would not be infinite because you only consider the data > values in the graph. > > Birte > >> >> Obviously, those will not give an answer, but some people might expect those to return surrogate blank nodes... a colleague of mine just came to me with that (in a different context), and I thought I might share it. >> >> Axel > > > > -- > Dr. Birte Glimm, Room 309 > Computing Laboratory > Parks Road > Oxford > OX1 3QD > United Kingdom > +44 (0)1865 283520 > -- Dr. Birte Glimm, Room 309 Computing Laboratory Parks Road Oxford OX1 3QD United Kingdom +44 (0)1865 283520
Received on Friday, 27 August 2010 22:33:16 UTC