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[SKOS] SKOS-XL property chains and OWL 2

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Mon, 09 Nov 2009 15:50:21 +0100
Message-ID: <4AF82C2D.8010807@few.vu.nl>
To: Thomas Bandholtz <thomas.bandholtz@innoq.com>
CC: Johan De Smedt <johan.de-smedt@tenforce.com>, SKOS <public-esw-thes@w3.org>, SWD WG <public-swd-wg@w3.org>
Hi Thomas,

Interesting issue, indeed:

> Hi Johan & Antoine,
> 
[snip]
> As [xl:literalForm] is defined as local datatype properties of skosxl:Label, the 
> property chain S57 will not work:
> 
> S57:      "The property chain (skosxl:hiddenLabel, skosxl:literalForm) 
> is a sub-property of skos:hiddenLabel."
> 
> You are right, OWL 2 introduces property chains for owl:ObjectProperty 
> but not for owl:DatatypeProperty. See
> http://www.w3.org/TR/2009/WD-owl2-new-features-20090611/#F8:_Property_Chain_Inclusion
> 
> There has been some discussion about "formal expression of property 
> chains" in the skos list, but no final clarification. See
> http://lists.w3.org/Archives/Public/public-esw-thes/2009May/0003.html
> 
> I think that Antoine's draft in
> http://lists.w3.org/Archives/Public/public-swd-wg/2009Mar/0043.html and
> is not valid OWL2 because he refers to datatype properties.
> 
> There are some valid examples in the OWL 2 primer, for instance:
> 
>  <rdf:Description rdf:about="hasUncle">
>    <owl:propertyChainAxiom rdf:parseType="Collection">
>      <owl:ObjectProperty rdf:about="hasFather"/>
>      <owl:ObjectProperty rdf:about="hasBrother"/>
>    </owl:propertyChainAxiom>
>  </rdf:Description>
> 
> To me it is not really clear why this pattern is restricted to object 
> properties in OWL 2, but it is.


Well, if that case, then I assume that for an OWL 2 version of the XL label/literalForm property chain, we would have to declare xl:LiteralForm to be an ObjectProperty as well (unless this is automatically inferred from just using the property in a property chain).
Note that I'm not really uncomfortable with that, as SKOS is already OWL Full.
And later, we could still try to make a OWL 2 DL version of SKOs-XL, by removing or adapting some of the triples that raise issues, as we did for the standard SKOS [1]

Antoine

[1] http://www.w3.org/2009/08/skos-reference/skos-owl1-dl.rdf

PS: btw I realize that this issue was raised by Johann a while ago, http://lists.w3.org/Archives/Public/public-esw-thes/2009Jul/0004.html...
Received on Monday, 9 November 2009 14:50:59 GMT

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