- From: Michael Schneider <m_schnei@gmx.de>
- Date: Wed, 18 Apr 2007 22:36:39 +0200
- To: public-owl-dev@w3.org
Hi, second time! Alan Ruttenberg wrote on Tue, 17 Apr 2007: > 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 If I correctly understand Alan's above citation from the draft, this is meant as an "EITHER s p o OR reification" (whatever form of reification will be used in the end). So, if I take my old but beloved OWL1.0 compliant ontology, which is serialized in RDF, and then cautiously start to add a few comments to all its axioms, I would not recognize the original RDF anymore, because all those s p o statements representing the axioms would now have been replaced by ugly and fat reifications? So still exactly the same ontology (annotation have no semantic implications, right?), but now with a largely different serialization. I would not like this! Really, I would prefer to have a "ALWAYS s p o AND ADDITIONALLY reification IF NEEDED FOR ANNOTATION". This would be more conservative, even my old OWL1.0 parser would recognize this ontology, because it would simply ignore the additional reification. The drawback would of course be that there would be one more statement within the serialization of an annotated axiom. But I could live with this easily: Reification adds four statements plus one for the annotation, so enlargement would be (at most) 20%. And specifically, RDF/XML provides me with a nice syntactic trick to get reification from an existing triple, by adding an 'rdf:ID' attribute to the predicate property, see http://www.w3.org/TR/rdf-primer/#example20 So my XML serialization would be even /smaller/ in comparison with reification without the s p o triple included. Bye, Michael
Received on Wednesday, 18 April 2007 20:31:48 UTC