[foaf-dev] FOAF DL

Antoine Zimmermann antoine.zimmermann at deri.org
Fri Jul 16 13:16:41 CEST 2010

Dear all,

I know that the compatibility of FOAF with OWL DL has been discussed a 
lot in the past (and still sometimes surfaces again).  However, I'm 
wondering, would it be reasonable to provide a DL version of FOAF in 
complement of the official FOAF ontology?
More generally, wouldn't it be reasonable to provide alternative 
versions of an ontology?  Think of XHTML: there are three different XML 
Schemas for XHTML [1].  One could imagine alternative versions like FOAF 
(Full), FOAF-DL, FOAF-lite...

Anyway, I did it: I've made a FOAF-DL ontology which modifies the FOAF 
ontology such that (1) it is in OWL 2 DL and (2) it maximally preserves 
inferences of the original FOAF ontology [2].

Interestingly, FOAF-DL is an OWL 2 RL ontology (in a nutshell, OWL 2 RL 
is a subset of OWL 2 DL with low computational complexity and that is 
compatible with rule-based inference engine).

You may notice that there are strange annotation properties for this 

<owl:Ontology rdf:about="http://purl.org/az/foaf#">
   <yoda:preferredVersion rdf:resource="http://xmlns.com/foaf/0.1/"/>

The Yoda vocabulary [3] is used to relate alternative versions of an 
ontology. Here, it is said that there is a preferred version, which is 
the official FOAF ontology.

Critiques to any of the previous comments are welcome.

[1] http://www.w3.org/TR/xhtml1-schema/#schemas
[2] The FOAF-DL ontology. http://purl.org/az/foaf
[3] Yoda: A Vocabulary for Linking Alternative Specifications of a 
Vocabulary. http://purl.org/NET/yoda

Antoine Zimmermann
Post-doctoral researcher at:
Digital Enterprise Research Institute
National University of Ireland, Galway
IDA Business Park
Lower Dangan
Galway, Ireland
antoine.zimmermann at deri.org

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