W3C home > Mailing lists > Public > public-owl-wg@w3.org > April 2009

Re: private review of Profiles, Section 4.3 (OWL 2 RL/RDF rules)

From: Ivan Herman <ivan@w3.org>
Date: Sat, 18 Apr 2009 10:22:24 +0200
Message-ID: <49E98DC0.3080904@w3.org>
To: Michael Schneider <schneid@fzi.de>
CC: Boris Motik <boris.motik@comlab.ox.ac.uk>, OWL 2 <public-owl-wg@w3.org>

Michael Schneider wrote:

>> xsd:nonNegativeInteger.
>> I see that this might be misunderstood; however, I don't believe that we
>> have a
>> problem formally speaking. We say that the rules are a bunch of
>> universally
>> quantified clauses, right? Now it all depends on how you interpret the
>> literals
>> in there. I believe these should be interpreted *semantically*. That is,
>> "0"^^xsd:nonNegativeInteger should be interpreted as the integer zero,
>> just like
>> "0"^^xsd:integer. Thus, if your data contains the latter but the rule
>> contains
>> the former, the rule still applies because the two values are
>> semantically
>> equivalent.
>> I haven't changed anything to this end.
> I'm fine with this. However, I think that we should have a word on this 
> in the document, or I believe it will become a FAQ, in particular for 
> implementers. (I wonder how Ivan treats cardinality restrictions in his
> implementation at the moment :-)) But this can be deferred for the 
> moment, since it is purely editorial.

I (instinctively:-) did more or less what Boris said. I take the literal
and I see if it can be interpreted as a value '1' or '0'. If so, I
follow the rule, if not, the rule is ignored.

> Ah, I see, I missed the point that ExactCardinality is not in the fragment.
> Just a point of clarification: I was only proposing to exactly 
> mirror the set of "max" rules. So in the case of exact-1, this 
> would have meant that there would have only been rules of the 
> kind "if there are two triples s p o1 and s p o2, then o1 = o2". 
> I did not ask for rules that introduces bNodes. But this 
> discussion is moot now, given your argument above.

I think it is better not to have this. If I look at (exact) cardinality
than I would expect something that is not only the 'max' rule. In this
sense _not_ having it among the rules may be cleaner, so to say.



> Cheers and thanks,
> Michael
> --
> Dipl.-Inform. Michael Schneider
> Research Scientist, Dept. Information Process Engineering (IPE)
> Tel  : +49-721-9654-726
> Fax  : +49-721-9654-727
> Email: michael.schneider@fzi.de
> WWW  : http://www.fzi.de/michael.schneider
> =======================================================================
> 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, Az 14-0563.1, RP Karlsruhe
> Vorstand: Prof. Dr.-Ing. Rüdiger Dillmann, Dipl. Wi.-Ing. Michael Flor,
> Prof. Dr. Dr. h.c. Wolffried Stucky, Prof. Dr. 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

Received on Saturday, 18 April 2009 08:23:02 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:42:12 UTC