- From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
- Date: Fri, 20 Feb 2009 22:04:47 +0000
- To: Ivan Herman <ivan@w3.org>
- Cc: Michael Schneider <schneid@fzi.de>, W3C OWL Working Group <public-owl-wg@w3.org>
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 >
Received on Friday, 20 February 2009 22:05:25 UTC