- From: Sandro Hawke <sandro@w3.org>
- Date: Sun, 01 Nov 2009 11:08:55 -0500
- To: Axel Polleres <axel.polleres@deri.org>
- cc: "Ivan Herman" <ivan@w3.org>, "Bijan Parsia" <bparsia@cs.man.ac.uk>, "Birte Glimm" <birte.glimm@comlab.ox.ac.uk>, "SPARQL Working Group" <public-rdf-dawg@w3.org>
> AFAIK, the intersection of RIF and OWL regarding datatypes is RIF. Indeed. We caught Ivan in the well-laid trap: he misunderstook rif:local and rif:iri as datatypes, but they are actually "symbol spaces", much closer to elements of the syntax than datatypes. -- Sandro > HTH, > > Axel > > On 1 Nov 2009, at 07:31, Ivan Herman wrote: > > > (I explicitly cc Axel here to put on his RIF WG member hat...) > > > > Hm. I must admit I did not really look into this, I simply took the > > terms used in the RDF Semantics document; more exactly, took over the > > URI-s RIF already uses. And you are right, this is not clear.... > > > > Bijan Parsia wrote: > >> On 1 Nov 2009, at 10:57, Ivan Herman wrote: > >> > >>> Birte, > >>> > >>> I was not at the call, sorry about that. >>> > >>> What I try to propose to the SW Coordination Group is the > >>> following set > >>> of URI-s > >>> > >>> http://www.w3.org/ns/entailment/Simple > >>> http://www.w3.org/ns/entailment/RDF > >>> http://www.w3.org/ns/entailment/RDFS > >>> http://www.w3.org/ns/entailment/D > >> > >> I'm sorry that I seem to be missing something, but what does D > >> indicate > >> exactly? The ambiguity that concerns me is that it could indicate > >> that > >> the system respects the semantics of "datatypes in general" or of a > >> specific set of datatypes. > >> > >> I presume it's the latter and the requisite datatype map is from: > >> http://www.w3.org/TR/rdf-mt/#dtype_interp > >> ? > >> > >> But that's not very well specified. It would be better to use the OWL > >> 2/RIF specs, I think, or some subset thereof. (E.g., we shouldn't > >> leave > >> open whether float and integer are disjoint.) > >> > > > > Sigh:-) > > > > I would probably take the intersection of the OWL and RIF. Ie, leave > > out > > owl:float and rif:local or rif:iri. Alternatively, we may restrict > > ourselves to what SPARQL defines as operand data types (11.1 in the > > current spec). > > > > Looking at the RIF document > > > > http://www.w3.org/TR/rif-rdf-owl/ > > > > RIF uses this URI to identify the common RIF-D model which... seems to > > leave the concrete datatype map open. > > > >> (I wonder whether using "D" is the best thing to do here. The term > >> "D-entailment" is pretty obscure as far as I can tell. And, in this > >> case, would it also entail RDF semantics? RDFS? Do we really need > >> RDF?) > >> > > > > The RIF document says: > > > > [[[ > > The profiles are ordered as follows, where '<' reads "is lower than": > > > > Simple < RDF < RDFS < D < OWL Full > > > > OWL DL < OWL Full > > ]]] > > > > where 'profiles' means (just to muddy the waters:-) the RIF profiles. > > > > The ordering makes sense but it is more than what the RDF Semantics > > seems to say for D. Axel, can you try to remember the reasoning > > behind this? > > > > If we want some sort of a compatibility (that is how the whole > > discussion on having separate and general URI-s for these started!) > > then > > we might want to take that over. It makes sense. > > > > Whether SPARQL really needs a separate RDF entailment here is a > > different question... I am not sure (but the URI would still exist) > > > > Cheers > > > > I. > > > > > > > > > >> Cheers, > >> Bijan. > > > > -- > > > > Ivan Herman, W3C Semantic Web Activity Lead > > Home: http://www.w3.org/People/Ivan/ > > mobile: +31-641044153 > > PGP Key: http://www.ivan-herman.net/pgpkey.html > > FOAF: http://www.ivan-herman.net/foaf.rdf > >
Received on Sunday, 1 November 2009 16:09:09 UTC