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Re: What about sub property chains for datatype properties? (ISSUE-8)

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Tue, 6 Nov 2007 21:56:52 +0000
Message-Id: <70049DCA-CAD7-4F94-B8D0-2A8ED40229B0@comlab.ox.ac.uk>
Cc: Michael Schneider <schneid@fzi.de>, Owl Dev <public-owl-dev@w3.org>
To: Uli Sattler <sattler@cs.man.ac.uk>

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 GMT

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