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Re: OWL 2.0 ...

From: Ian Horrocks <horrocks@cs.man.ac.uk>
Date: Sat, 4 Jun 2005 07:43:36 +0100
Message-Id: <3cafe4477d20292bf91126821335fb8d@cs.man.ac.uk>
Cc: public-owl-dev@w3.org, Jim Hendler <hendler@cs.umd.edu>
To: Paul Gearon <gearon@itee.uq.edu.au>

On 3 Jun 2005, at 14:53, Paul Gearon wrote:

>
> Going back a couple of months now...
>
> On 07/04/2005, at 11:14 PM, Jim Hendler wrote:
>>  (NOTE: This is a private message, it has no link to the Sem Web  
>> activity, or anything else -- I write this wearing my professor hat!)
>>
>> In recent days I've been attending a lot of meetings where I have  
>> been approached by people talking about not just the limitations of  
>> the current OWL (something I've been hearing about for a long time  
>> :-)) but actually talking about proposed technical solutions.   I  
>> think it would be good to start to collect some of these and to think  
>> a bit about those things that we might want to see go into some  
>> future OWL version
>>   There's a wide variety of these things going from simple extensions  
>> to OWL (such as adding qualified restrictions, having an  
>> owl:allDisjoint , etc.)  to adding some standard ways of doing common  
>> things in other KR langauges  (part-whole, bounded transitivity,  
>> probability models)  or going beyond to new concepts in Sem Web (new  
>> models of partial import, named ontology segments, etc.)
>>   I'd like to hear what people are working on, or what people need -  
>> this way we'll have these ideas on record for the eventual next  
>> generation of OWL technology.
>
> This may appear quite na´ve, but I've noted that OWL permits many of  
> the accessibility relationships of modal logic (transitivity,  
> reflexivity, symmetry) but not relationships that are Euclidean.  What  
> I mean, is to say for a relationship R1:
> R1(A,B)
> R1(A,C)
> => R2(B,C)
>
> For some relationship R2.  This would seem useful in a case like the  
> property "parentOf" if it were to relate to "siblingOf".
>
> At the moment this sort of thing is done with rule systems, but it  
> seems to me that the way relationships relate to each other is also a  
> part of an ontology.  Rule systems are often very specific, while  
> ontologies are much more general, so I think it's better to express a  
> concept in an ontology, if possible.
>
> The above example relies on R2 being symmetric, but if such a  
> construct were describable in OWL then perhaps non-symmetric versions  
> could also be expressed?  This would create the possibility of  
> describing more complex relationships, like "uncleOf".
>
> As I said, this is probably na´ve, but I've been wondering about  
> expressing relationships between properties for a while.  I'd  
> appreciate any feedback on the problems this sort of thing would  
> cause.

Paul,

Sorry to be self publicising, but I think you will find at least some  
of the answers in a paper that Ulrike Sattler and I wrote that deals  
with adding complex role inclusion axioms to the logics that underly  
OWL [1]. A shorter conference version is available on-line at [2]. The  
short answer is that extension in this direction is possible, but that  
care is needed in order to preserve decidability.

Ian

[1] Ian Horrocks and Ulrike Sattler. Decidability of SHIQ with complex  
role inclusion axioms. Artificial Intelligence, 160(1-2):79-104,  
December 2004.
[2]  
http://www.cs.man.ac.uk/~horrocks/Publications/download/2003/ 
HoSa03a.pdf

>
> Regards,
> Paul Gearon
>
>
>
Received on Saturday, 4 June 2005 18:41:16 GMT

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