W3C home > Mailing lists > Public > public-owl-wg@w3.org > June 2008

Re: Issue-114

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Mon, 30 Jun 2008 22:25:56 +0100
Message-Id: <D513BDF7-FDDA-4991-84B7-C28994900EA5@cs.man.ac.uk>
Cc: Rinke Hoekstra <hoekstra@uva.nl>, OWL Working Group WG <public-owl-wg@w3.org>
To: Alan Ruttenberg <alanruttenberg@gmail.com>

On Jun 30, 2008, at 9:26 PM, Alan Ruttenberg wrote:

> On Jun 30, 2008, at 2:46 PM, Rinke Hoekstra wrote:
>
>> Hi Alan, Michael,
>>
>> On 30 jun 2008, at 19:59, Alan Ruttenberg wrote:
>>> After discussion with Michael, we agreed to narrow this issue as  
>>> follows: We propose that the only punning in OWL is against  
>>> individuals - that is, anything named in OWL can have an  
>>> individual with the same (punned name).
>>
>> Could you please clarify what the underlying reason is for this  
>> restriction? Object/datatype property punning and class/datatype  
>> punning were problems because of a compatibility issue with OWL  
>> Full. Is there a similar problem with class/property and  
>> individual/property punning?
>
> There is no problem with individual/property punning - this is  
> included as valid in my proposal. There has never been, as far as I  
> am aware, a call for class/property punning.

Sure there has.

	1) To handle more RDF graphs. (class/property punning is in OWL  
Full, with exactly the same semantics.)
	2) To handle various integration/alignment situations.

Furthermore, these are already in and in OWL2 implementations.

>> If the restriction is based on an apparent lack of use cases I'm  
>> sure with a little effort we could come up with several. For  
>> instance,
>>
>> 1) The use of elephant and mouse properties to represent 'all  
>> elephants are bigger than all mice' (Markus' paper). The trick is  
>> to bridge the gap between TBox and RBox by making e.g. the class  
>> 'elephant' equivalent to a self restriction on the 'elephant'  
>> property. Role inclusion axioms can then be used (together with  
>> the universal role) to connect all elephants to all mice. I feel  
>> that this is a case where class/property punning is appropriate.
>
> In the case of individual/xx punning, we have the prospect (in DL)   
> of (eventually)  saying x (individual) sameAs y  (individual) => x  
> (type specific equivalence) y, In OWL full this is already part of  
> the semantics.
>
> How should this work with punning between properties and classes?

The same (effectively) as in OWL Full, i.e., punning.

>>  Having just class/individual punning is hard to defend (in  
>> particular because, at least in my view, most cases for class/ 
>> individual punning is just bad practice)
>
> It may be bad practice, but is is requested. To the extent that we  
> are chartered to provide features that have been identified by  
> users as widely needed,

Actually, I don't see that we're chartered to do that:

"""The mission of the OWL Working Group, part of the Semantic Web  
Activity, is to produce a W3C Recommendation that refines and extends  
OWL. The proposed extensions are a small set that:"""

I do think it's a good idea though.

> I think it ought to be a consideration in choosing what is in and  
> outside OWL. If we don't get rich annotations, the class and  
> property to instance punning will provide features that can not  
> otherwise be met.

The starting point is OWL 1.1. I think we should deviate from  
included features that have been interoperably implemented only when  
there are clear and strong arguments against them.

Cheers,
Bijan.
Received on Monday, 30 June 2008 21:26:29 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 30 June 2008 21:26:31 GMT