- From: Ivan Herman <ivan@w3.org>
- Date: Fri, 20 Feb 2009 20:29:57 +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: <499F04B5.5070101@w3.org>
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
Received on Friday, 20 February 2009 19:31:31 UTC