- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Fri, 2 Oct 2009 10:12:24 +0200
- To: Kevin Tyson <kevin.tyson@gmail.com>
- Cc: semantic-web@w3c.org
- Message-ID: <9d93ef960910020112t71459ab0sec0915dc974cfe04@mail.gmail.com>
Hi Kevin If I understand correctly, this does not alter the semantics of the covering > axiom that can be implemented today using disjoint classes which in union > comprise the equivalent class or super class of the covered class. > Not sure I catch exactly what you mean here, but my hunch is the answer is "no". OWL 2 provides just a shortcut to avoid the declaration of n˛ pairs of disjoint classes (unless I miss something) > What I don't understand is why an instance of the covered class does not > create an inconsistency. > Is this an artifact of the tools, in my case pellet and Protege 4, or is an > instance of a covered class which is not also an instance of a covering > class consistent? > That's something rather counter-intuitive. but there is no inconsistency in declaring x to be a direct instance of A when A is the union of B and C (disjoint or not). In this case, the ontology says that x is either in B or C (and not in both if the union is disjoint), but the triples at hand do not allow to conclude in which. The fact that x is an instance of A can even in some cases be entailed, not declared. Suppose you have defined a property p of which domain is A, if x p y then x is an instance of A. Of which you entail that x is either in B or C. No more no less. Bernard > TIA, > Kevin > > On Thu, Oct 1, 2009 at 3:46 AM, Bernard Vatant <bernard.vatant@mondeca.com > > wrote: > >> Kevin >> >> I would say DisjointUnion in OWL 2 is exactly what you are looking for >> http://www.w3.org/TR/2009/PR-owl2-new-features-20090922/#F1:_DisjointUnion >> >> Best >> >> Bernard >> >> 2009/9/30 Kevin Tyson <kevin.tyson@gmail.com> >> >>> Greetings,Is it possible to create a covering axiom such that any >>> instances of the covered class must be a direct instance of one of the >>> covering classes?Such a structure would be analogous to the "abstract >>> super class" pattern popular in some O-O programming and modeling languages. >>> TIA, >>> Kevin >>> >>> -- >>> Kevin P. Tyson >>> Kevin.Tyson@gmail.com >>> >> >> >> >> -- >> Bernard Vatant >> Senior Consultant >> Vocabulary & Data Engineering >> Tel: +33 (0) 971 488 459 >> Mail: bernard.vatant@mondeca.com >> ---------------------------------------------------- >> Mondeca >> 3, cité Nollez 75018 Paris France >> Web: http://www.mondeca.com >> Blog: http://mondeca.wordpress.com >> ---------------------------------------------------- >> > > > > -- > Kevin P. Tyson > Kevin.Tyson@gmail.com > -- Bernard Vatant Senior Consultant Vocabulary & Data Engineering Tel: +33 (0) 971 488 459 Mail: bernard.vatant@mondeca.com ---------------------------------------------------- Mondeca 3, cité Nollez 75018 Paris France Web: http://www.mondeca.com Blog: http://mondeca.wordpress.com ----------------------------------------------------
Received on Friday, 2 October 2009 08:13:29 UTC