Re: OWL2DL ontology is a graph or a set of axioms?

On Mar 8, 2015, at 12:58 PM, Leila Bayoudhi <bayoudhileila@yahoo.fr> wrote:

> Hi,
> Please, I want to check some points:
> 1/can we consider OWL2DL ontology as set of axioms?

Yes. Pretty much any ontology may be considered in this way, in fact. Strictly speaking, OWL2 ontologies have other structure including annotations and names and importations, but the core idea is that of a set of axioms. 

> Or does the OWL2DL ontology document is it a set of axioms
> 2/Most of works in litterature consider it as graph? Are they right?

That is also correct. OWL2, like many formalisms, can be represented in a variety of forms using different syntax conventions. All the W3C standard formalisms (RDF, RDFS, OWL, OWL2) can be encoded in RDF, and any RDF encoding is correctly described as an "RDF graph" (which is not however the same meaning as "graph" in mathematical graph theory). So an OWL2 ontology encoded in RDF is indeed an RDF graph. However, the same ontology can also be written in other syntaxes. However it is encoded, it is still correct to think of it basically as a set of axioms. 

> 3/ According the OWL2  structural specification, is it considered as a set of axioms or graph?

A set of axioms, more or less. Strictly, a set of axioms and anotations plus an optional IRI: see figure 1 in http://www.w3.org/TR/owl2-syntax/#Ontologies

> 4/ Please, if I will work on OWL2DL ontology,:
>     -Must I refer  essentially to OWL 2 Web Ontology Language Direct Semantics (Second Edition)?

That would be the simplest and most direct semantics to use, yes. (You *could* use the RDF-compatible semantics - they are proved to be equivalent for OWL2/RDF - but unless you are already very familiar with RDF encodings, this is likely to add needless complexity to your life.)

Hope this helps. 

Pat Hayes

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> OWL 2 Web Ontology Language Direct Semantics (Second Edition)
> OWL 2 Web Ontology Language Direct Semantics (Second Edition) W3C Recommendation 11 December 2012 This version: http://www.w3.org/TR/2012/REC-owl2-direct-semantics-20121211/ Latest version (series 2):
> Afficher sur www.w3.org
> Aperçu par Yahoo
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>    - Have I to use Direct Model-Theoretic Semantics for OWL 2 in order to introduce the OWL2DL ontology (in my papers)?
> Regards and thanks in advance.
>  

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Received on Monday, 9 March 2015 00:01:32 UTC