- From: Carsten Lutz <clu@tcs.inf.tu-dresden.de>
- Date: Wed, 23 Apr 2008 19:18:09 +0200 (CEST)
- To: Rinke Hoekstra <hoekstra@uva.nl>
- Cc: mak@aifb.uni-karlsruhe.de, Michael Schneider <schneid@fzi.de>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, public-owl-wg@w3.org
- Message-id: <Pine.LNX.4.64.0804231914440.2230@frege.inf.tu-dresden.de>
On Wed, 23 Apr 2008, Rinke Hoekstra wrote: > > On 23 apr 2008, at 18:30, Markus Krötzsch wrote: >> I agree, but I think it is not quite so simple. The main issue here might >> be >> that, while many rules can be expressed in OWL2, some of these encodings >> would violate the structural restrictions without need. I suggest we >> consider >> at least some special cases of rules here to waive that restriction, and >> make >> room for future rule interfaces on top of OWL2. I agree that we should not >> make a new rule language (if anything, one would take OWL2 rules to RIF, I >> guess). > > Hi Markus, > > I guess I agree with you on this point... it would be a shame to have the > structural restrictions get in the way of something that *can* be expressed > without changing the semantics. Aren't we then just speccing an ill-matched > syntax? > > How big / numerous do you expect the special cases to be? To me, this sounds like opening Pandora's box. I guess there are loads of special cases that one could allow. Where to start and where to stop? Moreover, people already find the non-structural restrictions awkward and difficult to understand. Now we want non-structural restrictions with (potentially a lot of) exceptions to them? <shiver>. I like the work of Markus on rules, but I am sceptical to start poking holes into our non-structural restrictions. Too ad-hoc. greetings, Carsten > -Rinke > > >> >> >> For people interested in a formal spec of a larger class of "OWL2 rules", I >> point to the following works of ours on the topic: >> >> http://korrekt.org/page/SROIQ_rules >> http://korrekt.org/page/ELP >> >> The main work here is to show that one can use rules (hence many other OWL >> 2 >> features) with our tractable profiles without hurting the polynomial >> reasoning. Moreover, there is also the Protege plugin by Francis Gasse (see >> OWLED-Washington papers, joint work with Volker Haarslev and Uli Sattler) >> to >> actually work with such rules -- maybe more concrete proposals could also >> emerge from that experience? >> >> Regards, >> >> Markus >> >> On Freitag, 18. April 2008, Michael Schneider wrote: >>> Hi! >>> >>> This has been an interesting exercise for me at that time, and helped me >>> to >>> better understand the power of sub property chains. It is nice to see that >>> something like this can actually be expressed within OWL 2 DL. But >>> directly >>> supporting this as a feature in the OWL language itself would look rather >>> strange to me. >>> >>> So I concur: +1 for REJECTING this issue. >>> >>> Cheers, >>> Michael >>> >>>> -----Original Message----- >>>> From: public-owl-wg-request@w3.org [mailto:public-owl-wg-request@w3.org] >>>> On Behalf Of Peter F. Patel-Schneider >>>> Sent: Friday, April 18, 2008 1:43 PM >>>> To: public-owl-wg@w3.org >>>> Subject: closing ISSUE-22 (special syntax for role rule) >>>> >>>> >>>> On 16 January 2008 Bijan added a note to the proposal for ISSUE-22: >>>> >>>> I think we should close this with no action. Here's why: >>>> >>>> 1) It's a new feature and there is no concrete proposal and I spent a >>>> few minutes trying to think of a syntax and had no good one other than >>>> the rule itself >>>> >>>> 2) Having just this one rule (which wouldn't be DL safe!) is very >>>> strange and might conflict with rule extensions >>>> >>>> 3) It seems that the best place for this is in a "Decidable swrl >>>> compiler" (as a visitor here was working on). There are *lots* of >>>> rules that you can compile using the new expressive property >>>> axioms. Why *this* one? Just because we thought of it? Better to >>>> encourage the development of these SWRL compilers and leave it to a >>>> "decidable fragments of SWRL" group. >>>> >>>> [Bijan Parsia] >>>> >>>> There does not appear to have been any futher discussion. >>>> >>>> I agree with Bijan's comments, and propose that ISSUE-22 be closed in >>>> this fashion. >>>> >>>> Peter F. Patel-Schneider >>>> Bell Labs Research >> >> >> >> -- >> Markus Krötzsch >> Institut AIFB, Universität Karlsruhe (TH), 76128 Karlsruhe >> phone +49 (0)721 608 7362 fax +49 (0)721 608 5998 >> mak@aifb.uni-karlsruhe.de www http://korrekt.org > > ----------------------------------------------- > Drs. Rinke Hoekstra > > Email: hoekstra@uva.nl Skype: rinkehoekstra > Phone: +31-20-5253499 Fax: +31-20-5253495 > Web: http://www.leibnizcenter.org/users/rinke > > Leibniz Center for Law, Faculty of Law > University of Amsterdam, PO Box 1030 > 1000 BA Amsterdam, The Netherlands > ----------------------------------------------- > > > > -- * Carsten Lutz, Institut f"ur Theoretische Informatik, TU Dresden * * Office phone:++49 351 46339171 mailto:lutz@tcs.inf.tu-dresden.de *
Received on Wednesday, 23 April 2008 17:18:46 UTC