- From: Bijan Parsia <bparsia@cs.man.ac.uk>
- Date: Fri, 26 Oct 2007 18:24:08 +0100
- To: "Elisa F. Kendall" <ekendall@sandsoft.com>
- Cc: public-owl-wg@w3.org
On 26 Oct 2007, at 18:09, Elisa F. Kendall wrote: > Hi, > > There are some things that we can do in the metamodel to specify > ordering - I'll need to investigate what is supported in OCL, as it > would be better, given that you want it to be optional, to provide > optional ordering constraints rather than creating mandatory > ordering requirements on the diagrams themselves. > > In the ODM metamodels for RDF and OWL 1.0, we separate the notion > of a statement occuring in a graph from that same statement > occurring in a particular document; RDF statements can be ordered > within the document(s) that they occur in. This isn't a constraint > on the core RDF metamodel, but in a separate, optional package > where we defined notions such as namespaces, URIs, documents, etc. > See section 10.7 in [1] for details. Jeremy and Dave Reynolds > helped us tease out the relationship between graphs and documents, > which may be useful for this discussion. > > We should think about whether you want to impose ordering > (optionally) on all possible concrete syntaxes or only in some cases As I discussed. I think we have to make it optional, i.e., give a "canonical RDF/XML", at least for RDF/XML. > - say, for example, yes if RDF/XML, no if N3. I'm not advocating > either way, but the decision to impose ordering, even optionally, > if done in the abstract syntax, would apply to all potential > concrete syntaxes. [snip] No, since in the mapping you could relax things. This, in fact, happens in the current RDF to Abstract/Functional syntax. In that case *parts* of axioms can be scattered in the RDF that cannot be scattered in the Functional syntax. Which way you do this is merely a matter of specification taste. Cheers, Bijan.
Received on Friday, 26 October 2007 17:22:55 UTC