- From: McBride, Brian <bwm@hplb.hpl.hp.com>
- Date: Fri, 29 Dec 2000 17:05:02 -0000
- To: "RDF Interest (E-mail)" <www-rdf-interest@w3.org>
> -----Original Message----- > From: Jonas Liljegren [mailto:jonas@rit.se] > Sent: 28 December 2000 23:36 > To: Graham Klyne > Cc: RDF interest group; Wraf development > Subject: Re: Klyne Contexts: 3. Statements sets in RDF > > > Graham Klyne <GK@Dial.pipex.com> writes: > > > It seems to me that, given an RDF graph, I should be able to extract > > an arbitrary subgraph (i.e. a subset of the statements) and > still have > > a valid RDF graph. The RDF approach to containers doesn't permit > > this, because (I think) the following is not valid per RDF M&S: > > > > [Foo] --rdf:type--> [rdf:Bag] > > [ ] --rdf:_1----> [Member1] > > [ ] --rdf:_3----> [Member3] The constraints on containers in m&s could be interpreted to apply to the abstract data model - i.e. all bags must have a contiguous set of members - in the abstract. However, a representation of the abstract model is perfectly free to represent only a part of the abstract model and is therefore free to represent only part of the bag and its contents. Under this interpretation, the above is valid. Anything else seems bizarre. > > I say that it must be valid. I would even allow: > > [Foo] --rdf:type--> [rdf:Bag] > [ ] --rdf:_1----> [Member1] > [ ] --rdf:_1----> [OtherMember1] > [ ] --rdf:_3----> [Member3] That would be a valid RDF model but would violate ontology cardinality constraints on the definition of bag. Brian McBride HPLabs
Received on Friday, 29 December 2000 12:05:10 UTC