[Pellet-users] Property chaining

[Evren Sirin]

On 3/18/08 7:50 AM, Rinke Hoekstra wrote:
> On 18 mrt 2008, at 12:29, Rinke Hoekstra wrote:
>   
>> I was just playing around with property inclusion axioms in Protege 4
>> and Pellet, and was surprised to notice that Pellet supports property
>> chains of the form:
>>
>> a.b -> c
>>     
>
> Actually, I shouldn't have been surprised as this is part of the OWL  
> 1.1 spec (as it currently stands)... but still, a pointer would be  
> nice :)
>   

There is a common misconception about what kind of property chains are 
allowed primarily because in the first formulation of the algorithm [1] 
only very restricted form of chains that you mention were allowed. In 
SROIQ, this restriction is relaxed and Pellet implements this relaxed 
version using the algorithm that was presented in the paper you cited 
(it is unfortunate that the example given in the abstract of that paper 
is exactly same as the restricted form which adds to the confusion). I 
have heard the same confusion about chains before so I think it would be 
a good idea for us to put this in the Pellet FAQ.

Cheers,
Evren

[1] I. Horrocks and U. Sattler.  Decidability of SHIQ with Complex Role 
Inclusion Axioms. In  Proc. of the International Joint Conference on 
Artificial Intelligence (IJCAI-2003), 2003.
http://lat.inf.tu-dresden.de/research/papers/2003/HorrocksSattler-IJCAI03.pdf

> -Rinke
>
>
>   
>> (i.e. the concatenation of a and b is a sub property of c)
>>
>> As I understood, SROIQ (per [1]) only supports either
>> a.b -> b
>> or
>> a.b -> a
>>
>> which is a lot more constrained than the other pattern.
>>
>> Is there any literature available on the implementation of property
>> chaining in Pellet?
>>
>> Thanks,
>>
>> 	Rinke
>>
>> [1] http://www.cs.man.ac.uk/~sattler/publications/sroiq-TR.pdf
>>
>> -----------------------------------------------
>> Drs. Rinke Hoekstra
>>
>> Email: hoekstra at 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
>> -----------------------------------------------
>>
>>
>>
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>
> -----------------------------------------------
> Drs. Rinke Hoekstra
>
> Email: hoekstra at 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
> -----------------------------------------------
>
>
>
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