W3C home > Mailing lists > Public > public-rdf-wg@w3.org > May 2012

Re: status of xsd:duration in RDF

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Mon, 21 May 2012 04:43:12 -0400
Message-ID: <4FBA0020.6010606@gmail.com>
To: Ivan Herman <ivan@w3.org>
CC: Pat Hayes <phayes@ihmc.us>, W3C RDF WG <public-rdf-wg@w3.org>
yes

On 05/21/2012 04:35 AM, Ivan Herman wrote:
> 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 08:43:48 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:25:49 GMT