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Re: 3rd Draft response to LC comment 30 (FH4)

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Sat, 21 Feb 2009 09:49:49 +0000
Message-Id: <744F29B7-D4E8-4226-A564-514299297542@comlab.ox.ac.uk>
Cc: Michael Schneider <schneid@fzi.de>, W3C OWL Working Group <public-owl-wg@w3.org>
To: Ivan Herman <ivan@w3.org>
I corrected a small typo (mean to means), but otherwise looks fine.

Ship it!

Thanks,
Ian

On 21 Feb 2009, at 08:13, Ivan Herman wrote:

> 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 09:50:27 GMT

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