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Re: Question about the topProperty

From: Rinke Hoekstra <hoekstra@uva.nl>
Date: Fri, 30 May 2008 10:38:38 +0200
Cc: Carsten Lutz <clu@tcs.inf.tu-dresden.de>, Michael Schneider <schneid@fzi.de>, public-owl-wg@w3.org
Message-Id: <7E541889-3A90-437B-BEA9-3956614D95EA@uva.nl>
To: mak@aifb.uni-karlsruhe.de

Tracker, this is also related to ISSUE-112

-Rinke

On 30 apr 2008, at 16:53, Markus Krötzsch wrote:

> On Mittwoch, 30. April 2008, Markus Krötzsch wrote:
>> On Freitag, 25. April 2008, Carsten Lutz wrote:
>>> On Thu, 24 Apr 2008, Michael Schneider wrote:
>>>> Hi!
>>>>
>>>> I have a question regarding the topProperty and the  
>>>> bottomProperty. If
>>>> these properties are going to be introduced into OWL 2, would  
>>>> they only
>>>> go into OWL-DL/Full, or can they also be included into each of the
>>>> profiles? Do these properties add to the semantic expressivity or  
>>>> to
>>>> the computational complexity of the profiles?
>>>
>>> For the case of EL++: the top and bottom properties can be  
>>> included. They
>>> do add to the expressivity, but do not increase computational  
>>> complexity.
>>> The latter is very easy to see by looking at existing EL++  
>>> algorithms,
>>> and I think it also follows from Markus' rule-extension of EL++.
>>
>> Yes, and this is still the case if you add things like role  
>> disjointness
>> and local reflexivity. If you add only universal properties, it is  
>> indeed
>> very easy to modify the existing algorithms.
>>
>> Anything above OWL DL can easily axiomatise a top property (using DL
>> pseudo-notation here, sorry):
>>
>> TOP SUBCLASSOF EXISTS R1.{a}
>> TOP SUBCLASSOF EXISTS R2.{a}
>> R1 o R2 SUBPROPOF U
> Typo. It should of course be:
>
> R1 o R2- SUBPROPOF U
>
> R1, R2 (properties) and a (individual) are of course new names, not  
> used
> anywhere else.
>
> -- Markus
>
>>
>> Then U is the universal. In other words: when you have defined your
>> semantics for TOP (thing), you also can define an according "cross  
>> product"
>> TOP x TOP easily. BottomProperties are even easier (see previous  
>> telco
>> logs).
>>
>> Cheers,
>>
>> Markus
>>
>>> greetings,
>>> 		Carsten
>>>
>>> --
>>> *      Carsten Lutz, Institut f"ur Theoretische Informatik, TU  
>>> Dresden
>>> * *     Office phone:++49 351 46339171
>>> mailto:lutz@tcs.inf.tu-dresden.de *
>
>
>
> -- 
> Markus Krötzsch
> Institut AIFB, Universität Karlsruhe (TH), 76128 Karlsruhe
> phone +49 (0)721 608 7362          fax +49 (0)721 608 5998
> mak@aifb.uni-karlsruhe.de          www  http://korrekt.org

-----------------------------------------------
Drs. Rinke Hoekstra

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-----------------------------------------------
Received on Friday, 30 May 2008 08:39:14 GMT

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