- From: Graham Klyne <Graham.Klyne@Baltimore.com>
- Date: Fri, 11 May 2001 16:06:38 +0100
- To: Brian McBride <bwm@hplb.hpl.hp.com>
- Cc: Martyn Horner <martyn.horner@profium.com>, w3c-rdfcore-wg@w3.org
I kind of like this general approach, but there's one thing I would pick up on at this point... At 01:43 PM 5/8/01 +0100, Brian McBride wrote: >What I'm hoping for here is something pretty simple that can serve as a >foundation on which we can build. > >I recently tried to articulate the working model that I use and it came >out something like this: > > There is a set of resources R. > > Each member of R is identified by a URI by which I mean: > > r1.uri == r2.uri <=> r1 == r2 > > i.e. two resources are identical if they have the same URI. > two resources with different URI's are different resources. > > There is a set E of entities. Entities are things like web pages, > numbers and trees in the park. > > There is a mapping D : R -> E. i.e. there is mapping which maps resources > to entities. I would say there is a mapping D : (RxP) -> E, where "P" is some arbitrary set of parameter data. I think something like this is needed to capture the idea that there may be an arbitrary number of entities associated with a resource, varying over time, content negotiation, location, identity of enquirer, etc., etc. Then there's the matter of "stateful" resources (or how to model HTTP PUT and "out of band" changes). > There is a notion of equivalence. > > Two resources r1 and r2 can be mapped by D to the same entity. In that > case > we say they are equivalent. > > equiv(r1,r2) <=> D(r1) = D(r2) > > and finally: > > D((p,s,o)) <=> D(p)(D(s),D(o)) I don't follow this last bit. >I present this, not because I claim it is correct, it doesn't deal with frag >id's >for example, but to suggest a language in which we can be clearer about >what we mean. Amen! It would be great if we could define a proper model theory for this stuff, because that would damp a lot of the circular discussions that seem to be happening. #g ------------------------------------------------------------ Graham Klyne Baltimore Technologies Strategic Research Content Security Group <Graham.Klyne@Baltimore.com> <http://www.mimesweeper.com> <http://www.baltimore.com> ------------------------------------------------------------
Received on Friday, 11 May 2001 13:32:43 UTC