- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Tue, 24 Feb 2009 09:43:40 -0500 (EST)
- To: alanruttenberg@gmail.com
- Cc: ivan@w3.org, public-owl-wg@w3.org
I worry about diluting the sections of the Profiles document with all this extra stuff. peter From: Alan Ruttenberg <alanruttenberg@gmail.com> Subject: Re: draft response for LC comment 32 CO1 Date: Mon, 23 Feb 2009 01:01:07 -0500 > While I think the general answer to Chime's comment is clear, I think > we would do well to add a couple of specific examples that demonstrate > a problem that someone might realistically run in to (ideally > constructed after a conversation with someone like Chime) to the > profiles document, and mention in the response that we intend to do > so. > > -Alan > > On Fri, Feb 20, 2009 at 5:01 AM, Peter F. Patel-Schneider > <pfps@research.bell-labs.com> wrote: >> From: Ivan Herman <ivan@w3.org> >> Subject: Re: draft response for LC comment 32 CO1 >> Date: Fri, 20 Feb 2009 09:33:06 +0100 >> >>> Well... although what you say is technically true, I would not find it >>> unreasonable if some characteristic _examples_ would be added to the >>> profile document for both cases that Chime refers to. This tough >>> rebuttal is a little bit to brisk for my taste, and we should have some >>> more explanation in our documents in my view. (Whether this is in the >>> profile or somewhere else like the primer is of course a different issue!) >>> >>> I just came up with some things that we could add: >>> >>> - For his first comment, we could, eg, refer to the fact that arbitrary >>> RDF graphs may include statements on the otherwise reserved vocabulary >>> with all kinds of funny consequences, or that they would allow defining >>> functional datatype properties whose consequences are a bit unpredictable. >> >> Fine. I'll put in something like: >> >> Arbitrary RDF graphs can include constructs that have surprising >> consequences. The reasons for these are many and varied, including >> effects on the "syntax" of OWL 2. Because there are so many ways in >> which the rules could incorrect, the working group has decided not to >> exactly characterize how the incorrectness arises, but instead has >> included a mention that arbitrary RDF graphs can affect the >> underpinnings of OWL, as follows: >> >> For ontologies satisfying the syntactic constraints described in >> Section 4.2, a suitable rule-based implementation will have desirable >> computational properties; for example, it can return all and only the >> correct answers to certain kinds of query (see Section 4.3 and >> [Conformance]). Such an implementation can also be used with arbitrary >> RDF graphs. In this case, however, these properties no longer hold — >> in particular, it is no longer possible to guarantee that all correct >> answers can be returned*, for example if the RDF graph uses the >> built-in vocabulary in unusual ways.* >> >>> - An example of the (missing) consequences due to the missing RDF(S) >>> axiomatic triples and some of the entailement rules is that >>> >>> rdf:_i rdf:type rdfs:ContainerMembershipProperty . (axiomatic rule) >>> meaning that >>> rdf:_i rdfs:subPropertyOf rdfs:member . (rdfs12 entailement rule) >>> >>> If these were around, an OWL RL user could handle container membership >>> more easily with those rules. >> >> I don't know whether *these* triples and rules provide an example of the >> missing inferences. Perhaps Boris can comment or provide an example. >> >>> Ivan >> >> peter >> >> >>> Peter F. Patel-Schneider wrote: >>>> [Draft Response for LC Comment 32:] CO1 >>>> >>>> Dear Chimezie, >>>> >>>> Thank you for your message >>>> http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0039.html >>>> on the OWL 2 Web Ontology Language last call drafts. >>>> >>>> Arbitrary RDF graphs can include constructs that have surprising >>>> consequences. The reasons for these are many and varied, including >>>> effects on the "syntax" of OWL 2. Because there are so many ways in >>>> which the rules could incorrect, the working group has decided not to be >>>> more explicit in the introduction to OWL 2 RL. >>>> >>>> There are an infinite number of RDFS axiomatic triples, so including >>>> them all in the OWL 2 RL rules does not directly lead to an effective >>>> rule implementation. There are some RDFS rules that produce >>>> consequences that are not relevant to the conclusions guaranteed by >>>> Theorem PR1. Listing all the "deficiencies" is not particularly easy, >>>> and would probably only confuse the issue. The working group has >>>> therefore decided not to be more explicit in the preamble to Theorem >>>> PR1. >>>> >>>> Please acknowledge receipt of this email to >>>> <mailto:public-owl-comments@w3.org> (replying to this email should >>>> suffice). In your acknowledgment please let us know whether or not you >>>> are satisfied with the working group's response to your comment. >>>> >>>> Regards, >>>> Peter F. Patel-Schneider >>>> on behalf of the W3C OWL Working Group >>>> >>>> No trees are known to have been harmed in the preparation of this >>>> response. >>>> >>> >>> -- >>> >>> 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 Tuesday, 24 February 2009 14:43:58 UTC