- From: Birte Glimm <birte.glimm@comlab.ox.ac.uk>
- Date: Sun, 1 Nov 2009 16:20:14 +0000
- To: Ivan Herman <ivan@w3.org>
- Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
[snip] >> In a sense ../entailment/OWL-Direct is the same as ../owl2-profile/DL >> and ../entailment/OWL-RDF-Based is the same as ../owl2-profile/Full. >> That is why DL and Full are not really profiles, but an OWL EL >> reasoner for example also applies the direct semantics of course. To >> be consistent with OWL though, not creating the Full and DL URIs might >> make sense. > > The way I understand OWL (2) is such that the linguistic restrictions > and the applied semantics are strictly separate. In theory I could use > the DL syntactical subset and apply RDF based semantics. And, at least > that is the way I understand (and I go to an area where my mathematical > understanding becomes sketchy...) on that subset it would not matter for > most of the cases, because the entailement results would be identical. > Am I far from the truth there? No, you are right. Entailments would be different for things like annotations I guess because under Direct Semantics these are ignored (have no semantics) whereas under RDF Based Semantics annotations still count. There were a view discussions around that and I am not sure I remember that rightly, but that's how I think it is. > That is why I think that entailement/OWL-Direct and owl2-profile/DL are > different, at least mathematically. If we talk about entailments we > should use, well, the entailments. And, well, as I said, the profile/DL > may not be that useful to have (although setting up a URI is one thing, > SPARQL may not be forced to use it...). Agreed. Birte > Ivan > >> >> Birte >> >> 2009/11/1 Ivan Herman <ivan@w3.org>: >>> 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 >>> http://www.w3.org/ns/entailment/OWL-Direct >>> http://www.w3.org/ns/entailment/OWL-RDF-Based >>> http://www.w3.org/ns/entailment/D >>> >>> http://www.w3.org/ns/owl2-profile/Full >>> http://www.w3.org/ns/owl2-profile/DL >>> http://www.w3.org/ns/owl2-profile/EL >>> http://www.w3.org/ns/owl2-profile/QL >>> http://www.w3.org/ns/owl2-profile/RL >>> >>> This seems to cover what the RIF group requires, it seems to be o.k. for >>> OWL (although you might want to convince Ian that the profile ones are >>> necessary) and seems to cover what SPARQL needs. >>> >>> What may be controversial whether the Full and DL profiles are really >>> necessary; after all, DL is a syntactic subset of OWL ie, it is a >>> profile although the term is not used. But if we do not need it, we can >>> just not create those for now. >>> >>> Does this work for you, ie, for SPARQL? >>> >>> Thanks! >>> >>> Ivan >>> >>> >>> >>> >>> Birte Glimm wrote: >>>> Hi all, >>>> in the telecon we shortly discussed whether we would need two URIs for >>>> the two OWL Semantics (RDF-Based and Direct (<- Model Theoretic, >>>> Description Logics)) or URIs for each OWL Profile. >>>> For RDF-Based seantics, we have two profiles: >>>> OWL Full and OWL RL >>>> OWL Full handles all legal RDF graphs and so does an OWL RL system. >>>> For OWL RL, if the input belongs to a certain fragment (the OWL RL >>>> fragment), then the system is guaranteed to sound and complete, >>>> otherwise the system might be incomplete. >>>> >>>> For Direct semantics we have three profiles: >>>> OWL QL, OWL EL, and OWL DL >>>> Any OWL DL reasoner can handle all three (but not arbitrary OWL Full). >>>> OWL EL reasoners can also handle OWL QL, and OWL QL reasoners do only >>>> OWL QL. >>>> Inputs outside of the supported fragment will be rejected, i.e., an >>>> OWL QL system works only on inpus that fall into the OWL QL fragment. >>>> OWL EL systems will accept inputs that fall into the EL (and thus also >>>> into the QL) fragment, etc >>>> >>>> The problem with using just one URI per semantics is that OWL QL and >>>> EL systems will possibly reject many input ontologies that are OWL DL >>>> because they are outside of their fragment. If we have just one URL, >>>> then I cannot know what the system will accept. It is trial and error. >>>> For RDF-Based semantics it seems to be less of an issue, but for >>>> Direct Semantics it would make more sense IMO to have different URIs >>>> and then it would be a bit wired to have only one for RDF-Based >>>> semantics, but three for Direct Semantics. >>>> >>>> Birte >>>> >>> -- >>> >>> 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 >>> >> >> >> > > -- > > 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 > -- Dr. Birte Glimm, Room 306 Computing Laboratory Parks Road Oxford OX1 3QD United Kingdom +44 (0)1865 283529
Received on Sunday, 1 November 2009 16:20:50 UTC