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Re: OWL species and subproperties of rdfs:label

From: Mark van Assem <mark@cs.vu.nl>
Date: Mon, 08 Jan 2007 13:57:04 +0100
Message-ID: <45A23FA0.1070102@cs.vu.nl>
To: Bernard Vatant <bernard.vatant@mondeca.com>
CC: Semantic Web <semantic-web@w3.org>, Tim Berners-Lee <timbl@w3.org>, Marc <marc@geonames.org>, public-esw-thes@w3.org

Hi,

The behaviour that you describe below does not occur in the Triple20 
tool [1] that I frequently use. It's more of a triple viewer than a 
full blown editor like Protege (editing is not as nicely supported), 
and it only partially supports OWL DL, but it doesn't do any funny 
things. What you stored is what you see, and what you added/removed is 
exactly what is in the stored file. It also has a category for 
resources that do not have an rdf:type, which is handy when debugging.

Cheers,
Mark.

[1] http://hcs.science.uva.nl/projects/Triple20/triple20.html

> SWOOP 2.3 just ignores such subproperty declarations when loading the 
> file, and they are removed when you save the file.
> 
> Protégé 3.2 behaviour is more tricky. The GUI just does not show such 
> properties but they are not removed from the RDF source by the Jena 
> backend, and stay in the RDF file when you save. But moreover, Protégé 
> insists that every owl:AnnotationProperty must be either 
> owl:DatatypeProperty or owl:ObjectProperty, and adds the former by 
> default. Which is IMO a very strange interpretation of OWL specification.
> 
> So, to sum it up, suppose I declare the following in the original ontology
> 
> <owl:AnnotationProperty     
> rdf:about="http://www.example.org/ontology#altName">
>  <rdfs:subPropertyOf     
> rdf:resource="http://www.w3.org/2000/01/rdf-schema#label"/>
> </owl:AnnotationProperty>
> 
> Loading and saving in SWOOP 2.3 yields back
> 
> <owl:AnnotationProperty 
> rdf:about="http://www.example.org/ontology#altName"/>
> 
> The subproperty declaration is deleted
> 
> Loading and saving in Protégé 3.2 yields back
> 
>  <owl:AnnotationProperty 
> rdf:about="http://www.example.org/ontology#altName">
>    <rdfs:subPropertyOf 
> rdf:resource="http://www.w3.org/2000/01/rdf-schema#label"/>
>    <rdf:type 
> rdf:resource="http://www.w3.org/2002/07/owl#DatatypeProperty"/>
>  </owl:AnnotationProperty>
> 
> The DatatypeProperty class is added
> 
> Now if I don't want to presume the property type and just declare
> 
> <rdf:Property     rdf:about="http://www.example.org/ontology#altName">
>  <rdfs:subPropertyOf     
> rdf:resource="http://www.w3.org/2000/01/rdf-schema#label"/>
> </rdf:Property>
> 
> SWOOP just ignores this declaration altogether, and the property is 
> killed when saving.
> Protégé does not show the property in the GUI, but Jena saves it in the 
> original form.
> 
> Well, all that is *very messy* indeed. Looks like that the semantics of 
> annotation subproperties is defined nowhere, and randomly implemented in 
> tools. OWL specification just says: this is not DL any more, go figure 
> what it means. I'm not even sure that a subproperty of an annotation 
> property is an annotation property. Is this entailed by RDFS semantics?
> 
> a:myProperty1      rdfs:subPropertyOf      b:yourProperty2
> b:yourProperty2       rdf:type      ex:SomePropertyType
> 
> Does the above entails in RDFS
> 
> a:myProperty1        rdf:type       ex:SomePropertyType
> 
> ?? (I guess yes, but maybe I'm wrong)
> 
> If yes, then applied to
> 
> skos:prefLabel      rdfs:subPropertyOf      rdfs:label   (by SKOS 
> vocabulary)
> rdfs:label         rdf:type      owl:AnnotationProperty   (by OWL 
> specification)
> 
> entails
> 
> skos:prefLabel      rdf:type      owl:AnnotationProperty
> 
> ... which is not the kind of entailment Protégé or SWOOP seem to support.
> 
> Do I miss something or is this really Terra Incognita in RDF semantics 
> world?
> 
> Thanks for enlightnments.
> 
> Bernard
> 

-- 
  Mark F.J. van Assem - Vrije Universiteit Amsterdam
        markREMOVE@cs.vu.nl - http://www.cs.vu.nl/~mark
Received on Monday, 8 January 2007 12:57:56 UTC

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