- From: Boris Motik <bmotik@cs.man.ac.uk>
- Date: Wed, 18 Apr 2007 10:20:29 +0100
- To: "'Jeremy Carroll'" <jjc@hpl.hp.com>
- Cc: "'Alan Ruttenberg'" <alanruttenberg@gmail.com>, <public-owl-dev@w3.org>, "'chris mungall'" <cjm@fruitfly.org>
Hello, I completely that it isn't pretty; however, the problem is that RDF does not allow you to express ternary relations. In the case of the axiom SubClassOf(Annotation(ap "bla") c1 c2) you actually have a ternary relationship: the participants are the annotation, c1, and c2. Since axioms can have more than one annotation, you actually need a way to represent relationships of arbitrary arity. The only way that I know of for encoding this into RDF is to reify the relationship. Sincerely yours, Boris > -----Original Message----- > From: Jeremy Carroll [mailto:jjc@hpl.hp.com] > Sent: 18 April 2007 10:17 > To: Boris Motik > Cc: 'Alan Ruttenberg'; public-owl-dev@w3.org; 'chris mungall' > Subject: Re: Axiom annotations > > > Reification isn't pretty. > This seems to be only about making something work in practice. > > Jeremy > > > > Boris Motik wrote: > > Hello, > > > > You are right - we overlooked this point. Would you mind logging this as > an > > issue at Google Code? > > > > The problem seems to be caused by the fact that, dating from OWL 1.0, > you > > could state only binary equivalences, disjointness axioms, etc. in OWL > RDF. > > OWL 1.1 inherits this limitation from OWL 1.0 (in order to be backwards > > compatible); however, as you notice, this has consequences regarding > > annotations. > > > > There are two fixes that I see: > > > > 1. One should provide an RDF encoding that does not break up > equivalences; > > then, we might tack on the annotations appropriately. > > > > 2. A hack would be to simply repeat the axiom annotation on each > generated > > equivalence. I am not particularly fond of this, but it is a > possibility. > > > > Thanks for pointing this out! > > > > Sincerely yours, > > > > Boris > > > >> -----Original Message----- > >> From: public-owl-dev-request@w3.org [mailto:public-owl-dev- > request@w3.org] > >> On Behalf Of Alan Ruttenberg > >> Sent: 18 April 2007 01:54 > >> To: public-owl-dev@w3.org > >> Cc: chris mungall > >> Subject: Axiom annotations > >> > >> > >> From http://webont.org/owl/1.1/rdf_mapping.html > >> > >>> Axioms with annotations are reified. If s p o is the RDF > >>> serialization of the corresponding axiom without annotations given > >>> in Table 2 and the axiom contains annotations Annotation(apIDi > >>> cti), 1 ? i ? n, then, instead of being serialized as s p o, the > >>> axiom is serialized as follows: > >>> > >>> _:x rdf:type owl11:Axiom > >>> _:x T(apIDi) T(cti) 1 ? i ? n > >>> _:x rdf:subject s > >>> _:x rdf:predicate p > >>> _:x rdf:object o > >> What happens when an Axiom serializes as multiple triples: > >> > >>> EquivalentClasses(c1 ... cn) => > >>> T(ci) owl:equivalentClass T(ci+1) 1 ? i ? n-1 > >> -Alan > > > > > > -- > Hewlett-Packard Limited > registered Office: Cain Road, Bracknell, Berks RG12 1HN > Registered No: 690597 England
Received on Wednesday, 18 April 2007 09:21:13 UTC