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

From: Uli Sattler <sattler@cs.man.ac.uk>
Date: Wed, 7 Nov 2007 17:31:52 +0000
Message-Id: <192D17B9-820D-4B22-8328-16D3E984B105@cs.man.ac.uk>
Cc: public-owl-wg@w3.org
To: Alan Ruttenberg <alanruttenberg@gmail.com>

...in a sense that adding it never changes the meaning/entailments of  
an ontology since such a subproperty chain is vacuously satisfied in  
every interpretation...possible. I doubt whether it would make sense,  
though.

Cheers, Uli

On 7 Nov 2007, at 16:53, Alan Ruttenberg wrote:

> So wait, am I hearing that this feature *could* be part of OWL 1.1DL?
> -Alan
>
> On Nov 7, 2007, at 11:42 AM, Uli Sattler wrote:
>
>>
>> On 7 Nov 2007, at 15:23, Alan Ruttenberg wrote:
>>
>>> Uli,
>>>
>>> Do the same decidability issues arise if only the last property  
>>> on the chain is a datatype property?
>>>
>>
>> not really, but semantically, it doesn't make sense to have  
>> datatype properties anywhere else but in the last place of a  
>> chain: a datatype value can only ever occur as the "filler" of a  
>> property (or "have in incoming property edge"), but never be  
>> "subject" of a property.
>>
>> Cheers, Uli
>>
>>> -Alan
>>>
>>> On Nov 7, 2007, at 8:32 AM, Jim Hendler wrote:
>>>
>>>>
>>>> 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 17:38:49 GMT

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