- From: Ivan Herman <ivan@w3.org>
- Date: Mon, 21 May 2012 10:35:46 +0200
- To: Pat Hayes <phayes@ihmc.us>
- Cc: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, W3C RDF WG <public-rdf-wg@w3.org>
Pat, Peter, Michael's question was actually the firs bullet point below; I think we have an agreement on that one and we can answer him accordingly. Is that correct? I agree on your course of action for XMLLiteral (which would also apply to rdf:HTML, in fact, if accepted by the WG) Ivan On May 19, 2012, at 17:38 , Pat Hayes wrote: > > On May 19, 2012, at 10:28 AM, Ivan Herman wrote: > >> Peter, >> >> this mail arrived as a question to your question, and I would like to answer it. I think that: >> >> - yes, duration would just be 'added' to the list but there is no planned change on the 'status' of these types regarding the RDF semantics. >> - actually, though not related to duration: would the fact that XMLLiteral becomes optional mean that D-entailment would not refer to this any more? > > It would refer to it, but it would be listed along with the XSD suite as being optional (part of a D) rather than built into RDF entailment. Yes, this should affect OWL and other entailment regimes which are built on RDF. I think it will make them easier, or else they are free to state that this datatype is built into OWL. Either way, something changes, if only editorial. > > We could help with this by saying that semantic extensions MAY choose to treat XMLLIteral as a built-in datatype. That lets them off the hook editorially. But we should check with them. > > Pat > > >> If so, does that affect OWL 2 and RIF? >> >> Thanks >> >> ivan >> >> Begin forwarded message: >> >>> Resent-From: public-owl-wg@w3.org >>> From: Michael Schneider <schneid@fzi.de> >>> Subject: Re: status of xsd:duration in RDF >>> Date: May 9, 2012 20:49:14 GMT+02:00 >>> To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com> >>> Cc: "public-owl-wg@w3.org" <public-owl-wg@w3.org>, Ian Horrocks <ian.horrocks@cs.ox.ac.uk>, "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org> >>> Archived-At: <http://www.w3.org/mid/4FAABC2A.80708@fzi.de> >>> List-Id: <public-owl-wg.w3.org> >>> >>> Hi Peter! >>> >>> Am 09.05.2012 17:09, schrieb Peter F. Patel-Schneider: >>>> Regardless of whether xsd:duration can make it into OWL 2, there is a >>>> question of whether anyone in this group knows of any reason why >>>> xsd:duration should not be added to RDF by the current RDF WG, aside >>>> from a desire to have the datatypes in OWL match those in RDF. >>>> >>>> Any comments? >>> >>> Two questions (with some implicit answers to your question): >>> >>> 1) What other datatypes are under consideration by the RDF WG to be "added to RDF"? There are a lot of datatypes being mentioned in the original RDF standard, which were not taken into account by the OWL 2 and RIF specs, such as xsd:gYear, xsd:gMonthDay, xsd:gDay, xsd:gMonth. So, one could argue, if these datatypes are going to be added to RDF (again), why should we (the OWL WG) then care about xsd:duration? It'll be then just yet another datatype that is in RDF but not in OWL 2 and RIF. >>> >>> 2) What does "adding to RDF" precisely mean? Mentioning the datatype somewhere in the spec by its name? Or making it a normative part of the RDF semantics? In RDF 1, the definitions of RDF-, RDFS- and D-interpretations only contained rdf:XMLLiteral as a normative part. There was one specific datatype map being mentioned in the chapter on D-entailment, called the "XSD datatype map" (the one with the non-OWL2 datatypes mentioned above), but it was not an official part of the semantics of any D-interpretation (as many people seem to believe), but was just a well-known datatype map, an example for how a "D" could look like (perhaps a "primus-inter-pares D", but not more). If "adding to RDF" is meant that way, then I would *not* care much, whether xsd:duration is included in the new version of the XSD datatype map or not. If, however, it is meant to become (together with its friends from the XSD datatype map) a normative part of any D-interpretation (which would be a big step from RDF 1), then I would care *much*, because any OWL 2 RDF-Based interpretation is a D-interpretation, and if all D-interpretations would include all the XSD datatypes from the RDF spec (plus, maybe, xsd:duration), this would mean that future OWL-N Full reasoners would have to support them all, which is quite a bit more than what OWL 2 Full reasoners are expected today (with possible implementation trouble here and there)! (To be mentioned: Most probably, this would then only be an issue for OWL N Full, not OWL N DL, as for current OWL 2 DL, the semantics and, in particular, the set of to-be-supported datatypes is specified independently from the RDF semantics specification). >>> >>> So far from my slightly RDF-Based/OWL Full-centric point of view. >>> >>> Best, >>> Michael >>> >>> -- >>> ......................................................... >>> Dipl.-Inform. Michael Schneider >>> Research Scientist, IPE / WIM >>> >>> FZI Forschungszentrum Informatik >>> Haid-und-Neu-Str. 10–14 >>> 76131 Karlsruhe, Germany >>> Tel.: +49 721 9654-726 >>> Fax: +49 721 9654-727 >>> >>> michael.schneider@fzi.de >>> www.fzi.de >>> >>> ......................................................... >>> Forschungszentrum Informatik (FZI) an der Universität Karlsruhe >>> Stiftung des bürgerlichen Rechts >>> Stiftung Az: 14-0563.1 Regierungspräsidium Karlsruhe >>> Vorstand: Dipl. Wi.-Ing. Michael Flor, Prof. Dr. Ralf Reussner, >>> Prof. Dr. Rudi Studer, Prof. Dr.-Ing. J. Marius Zöllner >>> Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus >>> ......................................................... >>> >> >> >> ---- >> Ivan Herman, W3C Semantic Web Activity Lead >> Home: http://www.w3.org/People/Ivan/ >> mobile: +31-641044153 >> FOAF: http://www.ivan-herman.net/foaf.rdf >> >> >> >> >> >> >> > > ------------------------------------------------------------ > IHMC (850)434 8903 or (650)494 3973 > 40 South Alcaniz St. (850)202 4416 office > Pensacola (850)202 4440 fax > FL 32502 (850)291 0667 mobile > phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes > > > > > > ---- Ivan Herman, W3C Semantic Web Activity Lead Home: http://www.w3.org/People/Ivan/ mobile: +31-641044153 FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Monday, 21 May 2012 08:32:27 UTC