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Re: Modeling a specific construct - please help

From: Pat Hayes <phayes@ihmc.us>
Date: Sun, 13 Sep 2009 13:56:07 -0700
Cc: Milan Zdravkovic <milan.zdravkovic@gmail.com>, public-owl-dev@w3.org
Message-Id: <708D4E47-F4C3-4588-B99D-35E5C894F1C5@ihmc.us>
To: Uli Sattler <sattler@cs.man.ac.uk>

On Sep 11, 2009, at 5:55 AM, Uli Sattler wrote:

> this is a difficult one:
>
> - I assume that Ab, B, and C are individuals, and that 'preceeds' is  
> 'directly preceeds' (otherwise, you should *not* conclude that A is  
> ConcurrentWith C.
>
> - you can introduce a transitive superproperty 'preceeds-trans' of  
> preceeds and find all instances of the class (e.g., via OWL API and  
> reasoner or via the DL query tab in Protege 4):
>
> (preceeds-trans value C) or (Inv(preceeds-trans) value C)
>
> if A is *not* in the answer to this query, then you can assume that  
> it is ConcurrentWith C.

Well, no, you cannot (validly) conclude this. This is a non-monotonic  
inference, which is not supported by the OWL semantics. While it may  
work in particular cases where you know that your data is complete in  
the required sense, it is not good practice to use such inference  
patterns in OWL, as they will (not may, but WILL) break in some cases.  
Think building a glass building over a known seismic fault.

Pat Hayes

>
> Cheers, Uli
>
>
> On 11 Sep 2009, at 12:27, Milan Zdravkovic wrote:
>
>> I am a beginner in OWL, working on specific process ontology. I  
>> have a problem in inferring the concurrency of process activities,  
>> for example - on basis of asserted A preeceds B and C preceeds B, I  
>> need to infer that: A isConcurrentWith C.
>> I was trying with modeling domain of isConcurrentWith with  
>> (Manchester syntax):
>> preceeds some (suceeds min 2 ProcessActivity)
>> , where preceeds properties are asserted and suceeds is inferred  
>> inverse property, but without success.
>>
>> Could you please help me on this ?
>>
>>
>>
>
>
>

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Received on Sunday, 13 September 2009 20:57:24 GMT

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