Re: status of xsd:duration in RDF

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