- From: <jos.deroo.jd@belgium.agfa.com>
- Date: Wed, 9 May 2001 16:45:32 +0100
- To: aswartz@upclink.com
- Cc: jos.deroo.jd@belgium.agfa.com, bwm@hplb.hpl.hp.com, martyn.horner@profium.com, w3c-rdfcore-wg@w3.org
> > Two resources r1 and r2 can be mapped by D to the same entity. In that
case
> > we say they are equivalent.
>
> I think this is a mistake -- there are many pages which return the same
> entity (the same set of text) but we cannot assume from this that they have
> equivalent resources. To do so would be a grave mistake.
> The entity returned may vary over time while the resource stays the same.
> Just because at one point in time they return the same entity does not mean
> that they always will.
maybe not if we talk about set-of-entities
which could go like:
there is a set of resources called R
there is a set of uris called U
there is a function f:U->R
for all u element of U there exists a r element of R such that f(u) = r
(or we could represent a resource r as a skolem function of it's uri u)
so u1 = u2 => f(u1) = f(u2)
so u1 = u2 => r1 = r2
there is a set of set-of-entities called S
(s element of S is meant to represent the possible states of a resource)
there is a function g:R->S
for all r element of R there exists a s element of S such that g(r) = s
for all u element of U there exists a s element of S such that g(f(u)) = s
so u1 = u2 => s1 = s2
--
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Wednesday, 9 May 2001 10:48:22 UTC