- From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
- Date: Tue, 6 Nov 2007 21:56:52 +0000
- To: Uli Sattler <sattler@cs.man.ac.uk>
- Cc: Michael Schneider <schneid@fzi.de>, Owl Dev <public-owl-dev@w3.org>
Uli, Thanks for the very useful and informative answer. Unfortunately, by sending the answer to this list and not public-owl- wg@w3.org it may not be seen by many members of the WG and also is not picked up by the issue tracker and so may be lost. I appreciate that Michael's original question was on the public-owl-dev@w3.org list, but it would help if you could also send this as a reply to [1] so that it gets into the system. Thanks, Ian [1] http://lists.w3.org/Archives/Public/public-owl-wg/2007Oct/0251.html On 5 Nov 2007, at 15:13, Uli Sattler wrote: > > Hi Michael, > > there are reasons why these sub-property chains are only made up of > object properties: decidability in OWL (DL and 1.1) relies on the > fact that "datatype consistency" can be checked for each object > separately, without referring to other objects and the values of > their datatype properties. If we would need to do this, we would > more likely be in trouble, and would need to > > - be much more careful about what datatypes and datatype predicates > to allow without loosing decidability and > - use more complex reasoning mechanisms that have, to the best of > my knowledge, only been described on paper and never been > implemented or tested. > > So, I can see your use case, but I don't think we know enough about > this yet. > > If you want to know more, check out > > Carsten Lutz and Maja Milicic. A Tableau Algorithm for Description > Logics with Concrete Domains and General TBoxes. Journal of > Automated Reasoning. To appear. > http://lat.inf.tu-dresden.de/~clu/papers/archive/jar06.pdf > > Carsten Lutz. Description Logics with Concrete Domains - A Survey. > In Philippe Balbiani, Nobu-Yuki Suzuki, Frank Wolter, and Michael > Zakharyaschev, editors, Advances in Modal Logics Volume 4. King's > College Publications, 2003. > http://lat.inf.tu-dresden.de/~clu/papers/archive/aiml4.ps.gz > > Cheers, Uli > > > > > On 2 Oct 2007, at 13:26, Michael Schneider wrote: > >> >> Hi! >> >> It just stroke me that there seem to be only Sub/Object/ >> PropertyChains in >> the current OWL-1.1 draft [1]. Does anyone know if there is a >> problem with >> also having sub property chains of the form >> >> SubDataPropertyOf( >> SubDataPropertyChain(R1 ... Rn-1 Dn) >> D ) >> >> where Dn and D are DataPropertyS (having compatible datatypes as >> their >> ranges), while R1 ... Rn-1 are ObjectPropertyS? >> >> With such a SubDataPropertyChain, one could for instance translate >> rules >> like: >> >> ?x hasFather ?y AND ?y hasFamilyName ?fn >> ==> ?x hasFamilyName ?fn >> >> with ?fn being an xsd:string, into an equivalent OWL axiom >> >> SubDataPropertyOf( >> SubDataPropertyChain(hasFather hasFamilyName) >> hasFamilyName ) >> >> In this case, the super property whould equal the final chain >> property (both >> 'hasFamilyName'). >> >> An example for a more general rule type (the analogon of the >> 'uncle' rule) >> would be: >> >> ?g containsUser ?u AND ?u hasUserID ?i >> ==> ?g containsUserWithID ?i >> >> where ?g would stand for some user group. Here, the DataPropertyS >> 'hasUserID' and 'containsUserWithID' differ from each other, >> because they >> are intended to have a different meaning. >> >> Any ideas, if this feature has a chance to enter the family of >> OWL-1.1 (or >> 1.2 :)) axioms? Or did I overlook some fundamental issue here? >> >> Cheers, >> Michael >> >> [1] OWL-1.1 Semantics >> http://www.webont.org/owl/1.1/semantics.html#2 >> >> -- >> Dipl.-Inform. Michael Schneider >> FZI Forschungszentrum Informatik Karlsruhe >> Abtl. Information Process Engineering (IPE) >> Tel : +49-721-9654-726 >> Fax : +49-721-9654-727 >> Email: Michael.Schneider@fzi.de >> Web : 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 >> Az: 14-0563.1 Regierungspräsidium Karlsruhe >> Vorstand: Rüdiger Dillmann, Michael Flor, Jivka Ovtcharova, Rudi >> Studer >> Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus >> > >
Received on Tuesday, 6 November 2007 21:57:28 UTC