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Re: ISSUE-91 informal semantics of ontology properties

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Wed, 2 Jan 2008 21:45:47 -0500
Message-Id: <8E7159E9-A45A-4006-AFC6-7EF345BBCA4C@gmail.com>
To: OWL Working Group WG <public-owl-wg@w3.org>

Note for tracker:  ISSUE-24 also speaks to the question of the  
meaning of the versioning properties.

-Alan

On Jan 2, 2008, at 2:29 PM, Rinke Hoekstra wrote:

>
> Hi Boris,
>
> To answer your question about ISSUE-91... you asked what this  
> 'meaning' or informal semantics of ontology properties in OWL 1.0  
> is that I was referring to. This is actually done in several places.
>
> The owl guide [1] section 6 says:
>
> "Ontology versions may not be compatible with each other. For  
> example, a prior version of an ontology may contain statements that  
> contradict the current version. Within an owl:Ontology element, we  
> use the tags owl:backwardCompatibleWith and owl:incompatibleWith to  
> indicate compatibility or the lack thereof with previous ontology  
> versions. If owl:backwardCompatibleWith is not declared, then  
> compatibility should not be assumed. "
>
> ... especially the last comes across as rather normative.
>
> Also section 7.4.3 in the reference [2]
>
> "An owl:backwardCompatibleWith statement contains a reference to  
> another ontology. This identifies the specified ontology as a prior  
> version of the containing ontology, and further indicates that it  
> is backward compatible with it. In particular, this indicates that  
> all identifiers from the previous version have the same intended  
> interpretations in the new version. Thus, it is a hint to document  
> authors that they can safely change their documents to commit to  
> the new version (by simply updating namespace declarations and  
> owl:imports statements to refer to the URL of the new version). If  
> owl:backwardCompatibleWith is not declared for two versions, then  
> compatibility should not be assumed.
>
> owl:backwardCompatibleWith has no meaning in the model theoretic  
> semantics other than that given by the RDF(S) model theory."
>
> Although this bit states that the ontology property has no  
> 'meaning' in the model theoretic semantics, there clearly is an  
> intended interpretation. By the way, the RDF(S) model theory  
> requires the range of the property to be an owl:Ontology, something  
> that will make Pellet, and other systems (eg. the OWL Validator) to  
> conclude that an OWL DL ontology is in OWL Full if it does not  
> contain the the type of the resource explicitly (P4 simply adds  
> this without complaining). See the wiki page on versions [3].
>
> I'm really not saying that we should introduce formal semantics for  
> these properties, but we should be careful in throwing away (or  
> rather, not mentioning) language elements from 1.0 without  
> documenting such a decision. And they do have meaning in the RDF- 
> sense.
>
> Cheers,
>
> 	Rinke
>
>
> [1] http://www.w3.org/TR/owl-guide/
> [2] http://www.w3.org/TR/owl-ref/#backwardCompatibleWith-def
> [3] http://www.w3.org/2007/OWL/wiki/Ontology_Versions
> -----------------------------------------------
> Drs. Rinke Hoekstra
>
> Email: hoekstra@uva.nl    Skype:  rinkehoekstra
> Phone: +31-20-5253499     Fax:   +31-20-5253495
> Web:   http://www.leibnizcenter.org/users/rinke
>
> Leibniz Center for Law,          Faculty of Law
> University of Amsterdam,            PO Box 1030
> 1000 BA  Amsterdam,             The Netherlands
> -----------------------------------------------
>
>
>
>
Received on Thursday, 3 January 2008 02:46:12 GMT

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