- From: Ivan Herman <ivan@w3.org>
- Date: Sat, 21 Feb 2009 09:13:33 +0100
- To: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
- CC: Michael Schneider <schneid@fzi.de>, W3C OWL Working Group <public-owl-wg@w3.org>
- Message-ID: <499FB7AD.3040200@w3.org>
We seem to have discussed this one to death:-)... anyway, I found the discussion on the FS useful for me at least! I have modified the Wiki site with the draft answer. I did add a half sentence, though, to answer to the question; the last sentence now reads: [[[ In the example you mentioned, for example, the "_:1" simply represents a blank node in the RDF graph, and this is indeed the only syntactic mean to define a blank node. ]]] See you soon! Ivan Ian Horrocks wrote: > I'm pretty sure that his main concern was w.r.t. backwards > compatibility. I suggest that we simply try the answer below and see > what he says. > > Ian > > On 20 Feb 2009, at 19:29, Ivan Herman wrote: > >> Hm, you made me uncertain:-( Re-reading his comments again I wonder >> whether his question is not about AS but whether it is possible, in >> the FS, to define anonymous nodes _without_ explicit naming. In which >> case the answer should be a 'no'... >> >> Ivan >> >> Ian Horrocks wrote: >>> It wasn't obvious to me that Frank was concerned with the AS. When he >>> said that "it's not clear from the doc. whether the OWL1 syntax is >>> still allowed", I imagined that he was really concerned about the RDF >>> syntax and the expressivity of the language. As I said in my email, >>> the AS has changed in many ways, and it seemed odd that Frank would >>> single out this one. >>> Anyway, I don't suppose that it would hurt to put back the paragraph >>> on AS, but I suggest putting it after the one about backwards >>> compatibility of the RDF. The result would be: >>> Dear Frank, >>> Thank you for your comment >>> <http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0037.html> >>> >>> on the OWL 2 Web Ontology Language last call drafts. >>> We also note the 'addendum' to your original comment in >>> <http://lists.w3.org/Archives/Public/public-owl-comments/2009Feb/0014.html> >>> >>> And we thank you for helping us avoiding further confusion on this >>> issue. >>> It is important to note that nothing changed on the RDF side, and that >>> the treatment of anonymous individuals in OWL 2 is fully backwards >>> compatible with that in OWL 1. Even on the structural syntax side, there >>> is no change in expressive power, but we restructured the syntax to be >>> in closer correspondence with RDF graphs to make it clearer that >>> anonymous individuals are in direct correspondence with blank nodes. In >>> the example you mentioned, for example, the "_:1" simply represents a >>> blank node in the RDF graph. >>> Concerning the usability of AS in OWL 2: if used as an exchange >>> syntax then, of course, OWL 1 ontologies written in AS may be input >>> to OWL 2 tools and remain valid ontologies. But we must emphasize >>> that this is an issue of the tool providers: the only _required_ >>> exchange syntax for OWL 2 ontologies being RDF/XML, it is up to the >>> tools to decide whether they would accept ontologies serialized in AS >>> (or in FS, for that matter). >>> We agree this isn't made very clear in the documents, and we will try to >>> improve the presentation. For example, we plan to add some explanatory >>> text into the New Features and Rationale document on the change of >>> syntax. >>> We hope this answers your concerns on this particular issue. >>> On 20 Feb 2009, at 12:10, Ivan Herman wrote: >>>> Ian, >>>> >>>> I do not mind using this text, but Frank explicitly asked whether AS is >>>> still usable. Why did you leave that part out? >>>> >>>> Ivan >>>> >>>> P.S. As an aside, although the text on FS/FOL came from an earlier >>>> version of the draft, as written by Bijan, I must admit that this >>>> argument seemed to be valid to me. The only way I can explain myself >>>> the >>>> order of the various arguments and parameters in the language is when I >>>> look at the way the same formulae would be written in FOL. But that may >>>> be only me, I do not mind taking that out... >>>> >>>> Ian Horrocks wrote: >>>>> Another issue with the proposed response is that I don't think it >>>>> clearly answers Frank's main concern (as I understand it), which is >>>>> backwards compatibility of the RDF syntax. I also wonder why you talk >>>>> about the FS being closer to FOL syntax -- I don't recall this being a >>>>> motivation and I doubt that it is relevant to Frank or to (m)any >>>>> other >>>>> people. Finally, w.r.t. the structural syntax, this has been >>>>> changed in >>>>> *many* respects, so I doubt that compatibility of the structural >>>>> syntax >>>>> is particularly relevant here. >>>>> >>>>> I therefore suggest the following response: >>>>> >>>>> >>>>> Dear Frank, >>>>> >>>>> Thank you for your comment >>>>> >>>>> <http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0037.html> >>>>> >>>>> on the OWL 2 Web Ontology Language last call drafts. >>>>> >>>>> We also note the 'addendum' to your original comment in >>>>> >>>>> <http://lists.w3.org/Archives/Public/public-owl-comments/2009Feb/0014.html> >>>>> >>>>> >>>>> And we thank you for helping us avoiding further confusion on this >>>>> issue. >>>>> >>>>> It is important to note that nothing changed on the RDF side, and that >>>>> the treatment of anonymous individuals in OWL 2 is fully backwards >>>>> compatible with that in OWL 1. Even on the structural syntax side, >>>>> there >>>>> is no change in expressive power, but we restructured the syntax to be >>>>> in closer correspondence with RDF graphs to make it clearer that >>>>> anonymous individuals are in direct correspondence with blank >>>>> nodes. In >>>>> the example you mentioned, for example, the "_:1" simply represents a >>>>> blank node in the RDF graph. >>>>> >>>>> We agree this isn't made very clear in the documents, and we will >>>>> try to >>>>> improve the presentation. For example, we plan to add some explanatory >>>>> text into the New Features and Rationale document on the change of >>>>> syntax. >>>>> >>>>> We hope this answers your concerns on this particular issue. >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> On 20 Feb 2009, at 11:08, Michael Schneider wrote: >>>>> >>>>>> Ivan wrote: >>>>>> >>>>>>> For example, one can refer to anonymous/blank nodes from >>>>>>> more than one place, hence a larger class of RDF graphs can be >>>>>>> expressed >>>>>>> in FS. >>>>>> >>>>>> I would like to see an example for something that can now be written >>>>>> in the Functional Syntax, for which there was no corresponding way to >>>>>> express it in the old Abstract Syntax. The global syntactic >>>>>> restrictions in Section 11.2 of the Structural Spec are pretty >>>>>> restrictive, AFAICT. >>>>>> >>>>>> Michael >>>>>> >>>>>> -- >>>>>> Dipl.-Inform. Michael Schneider >>>>>> Research Scientist, Dept. Information Process Engineering (IPE) >>>>>> Tel : +49-721-9654-726 >>>>>> Fax : +49-721-9654-727 >>>>>> Email: schneid@fzi.de >>>>>> WWW : http://www.fzi.de/ipe/eng/mitarbeiter.php?id=555 >>>>>> >>>>>> ============================================================================== >>>>>> >>>>>> >>>>>> >>>>>> FZI Forschungszentrum Informatik an der Universität Karlsruhe >>>>>> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe >>>>>> Tel.: +49-721-9654-0, Fax: +49-721-9654-959 >>>>>> Stiftung des bürgerlichen Rechts >>>>>> Stiftung Az: 14-0563.1 Regierungspräsidium Karlsruhe >>>>>> Vorstand: Prof. Dr.-Ing. Rüdiger Dillmann, Dipl. Wi.-Ing. Michael >>>>>> Flor, >>>>>> Prof. Dr. rer. nat. Dr. h.c. Wolffried Stucky, Prof. Dr. rer. nat. >>>>>> Rudi Studer >>>>>> Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus >>>>>> >>>>>> ============================================================================== >>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> -- >>>> >>>> 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 >> > -- 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 Saturday, 21 February 2009 08:14:07 UTC