- From: Jeen Broekstra <jeen@aduna.biz>
- Date: Thu, 03 Feb 2005 10:12:02 +0100
- To: Kianoush Eshaghi <Kianoush.Eshaghi@metadat.at>
- Cc: 'RDF interesting groupe' <www-rdf-interest@w3.org>
Kianoush Eshaghi wrote: > A vocabulary (charily asserted an "ontology")can be modeled by RDFS > according to object-oriented technique, for example a property can be > inherited by some super property. > > My question is does my property inherit the all domains and ranges of > its super property, if I let inherit the property? No, it does not, save by implication (at least in the normative intensional semantics of RDFS - http://www.w3.org/TR/rdf-mt/). What I mean is this: suppose we have a property p with a domain A : p rdf:type rdf:Property. p rdfs:domain A. and we create a subProperty q : q rdfs:subPropertyOf p. RDFS does _not_ entail: q rdfs:domain A. However, whenever we _use_ the property q in a statement, like so: x q y. Because q is a subProperty of p we infer (rule rdfs7): x p y. ...and because the domain of p is A we infer (rule rdfs2): x rdf:type A. So "implicitly" the domain is carried over the subproperty. If you look at the RDF Semantics section 4.1 and 7.3.1, you will find there a specification of extensional entailments. In such a stronger, extensional interpretation, the domain restriction _is_ explicitly inherited. Most implementations of RDF/RDFS reasoners stick to the intensional semantics, however. HTH. Jeen -- Jeen Broekstra Aduna BV Knowledge Engineer Julianaplein 14b, 3817 CS Amersfoort http://aduna.biz The Netherlands tel. +31(0)33 46599877 fax. +31(0)33 46599877
Received on Thursday, 3 February 2005 09:11:03 UTC