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Re: ISSUE-8 (dataproperty chains): REPORTED: add chains ending with data properties)

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Wed, 7 Nov 2007 08:32:49 -0500
Message-Id: <74800932-D070-4F44-A0BD-FA4970FC7DB0@cs.rpi.edu>
Cc: public-owl-wg@w3.org
To: Uli Sattler <sattler@cs.man.ac.uk>

So we can allow this in OWL 1.1 Full, but not in OWL 1.1. DL since it  
is only related to decidability which is the primary differentiator  
between DL and Full.  So I propose that we include this construct in  
1.1 but make it clear that using it will take you to Full.
  Since this is on agenda for discussion at a meeting I cannot  
attend, I state for the record that RPI would oppose any closure of  
this issue that would not allow a property chain to end in a datatype  
property in the RDF realization
  -JH
p.s. I realize now that my primary problem with the structural  
document relates to this DL v. Full issue, and will take that up in  
another thread.


On Nov 7, 2007, at 5:12 AM, Uli Sattler wrote:

>
> Dear all,
>
> a few days ago, I sent this email below as an answer to Owl Dev  
> only, overlooking that I should have sent it to owl-wg as well...so  
> here it is with a bit of delay, cheers, Uli
>
>
> 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
>>>
>>>
>

"If we knew what we were doing, it wouldn't be called research, would  
it?." - Albert Einstein

Prof James Hendler				http://www.cs.rpi.edu/~hendler
Tetherless World Constellation Chair
Computer Science Dept
Rensselaer Polytechnic Institute, Troy NY 12180
Received on Wednesday, 7 November 2007 13:33:01 GMT

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