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Re: IFP and datatype properties

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Sun, 11 Mar 2007 12:32:43 -0400
Message-Id: <7D286483-AF68-455A-831C-090FFD3A28E2@gmail.com>
Cc: Ulrike Sattler <sattler@cs.man.ac.uk>, Alex Tucker <alex@floop.org.uk>, public-owl-dev@w3.org
To: Denny Vrandecic <dvr@aifb.uni-karlsruhe.de>

There is already a distinction among properties "complex" versus  
others and restrictions on which can be made transitive based on that.
That one is a little simpler because one can see the conflict only  
looking at only property definitions.

This one would need to look at both a property declaration and the  
datatype that the property is used with. I'm not familiar enough with  
datatype inferencing to know how problematic this might me. I'm  
imagining the use of a datatype ifp in a context where it takes the  
reasoner to realize that the effective datatype is bounded - you  
can't just tell by looking at what's explicitly stated.

There's one case I'm aware of this in the former ("complex" property)  
case, where if a property can't have any values (e.g. cardinality 0),  
is inferred to be (trivially) transitive, but it doesn't hurt.


On Mar 11, 2007, at 12:11 PM, Denny Vrandecic wrote:

> Couldn't the combination of datatype IFPs and bounded subtypes be  
> restricted? Or, to put it differently, allow datatype IFPs only to  
> infinite concrete domains.
> This would certainly be enough to allow for datatype IFPs to be  
> used like they are in FOAF, for example.
> denny
> Alan Ruttenberg wrote:
>> That's what I think. Or at least not problems worse than what you  
>> have with object properties. But there also needs not to be a way  
>> to create large bounded subtypes. (since things true of the class  
>> would be true of the subclass)
>> So integers are infinite, but OWL1.1 allows there to be range  
>> subtypes.
>> -Alan
>> On Mar 11, 2007, at 11:22 AM, Denny Vrandecic wrote:
>>> Sorry if the question seems stupid --
>>> Ulrike Sattler wrote:
>>>> let me explain this dependency a little: IFPs (whether they are  
>>>> present explicitly or via the work-around described by Alan)  
>>>> should be harmless
>>>> - in case where you have individual names (even many of them),  
>>>> say a1, a2, ...., a1000000,... and all of the are related via  
>>>> the datatype property "hasID" to  some integer, and you have  
>>>> declared hasID as inverse functional: now, in case that there  
>>>> are 2 individuals, say a17 and a23, that have the same hasID- 
>>>> filler, then a17 and a23 will be identified.
>>> So if we require the concrete domain an inverse functional  
>>> datatype property points to being always of infinite size there  
>>> is no problem?
>>> denny
Received on Sunday, 11 March 2007 16:33:33 UTC

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