Re: Issues danc-01 Re: 2 formalities in RDF concepts

On Wed, 2003-01-29 at 03:41, Jan Grant wrote:
> On Tue, 28 Jan 2003, Dan Connolly wrote:
> 
> > > Jeremy's talking about *syntactic* equality (ie, "X equals Y" means
> > > "every expression involving X can be rewritten with Y substituted for it
> > > and the expression's value is preserved"),
> >
> > Hmm... I wasn't familiar with that idea before... I'll have
> > to think it over.
> >
> > But my intuition says the difference between syntactic
> > equality and identity matters to the RDF spec.
> >
> > For example, if X and Y are distinct graphs that
> > art syntactically equal, what's the cardinality
> > of the set {X, Y}? It's 2, right?
> >
> > The model theory spec does stuff like putting
> > graphs into sets, and I think it matters what
> > the cardinality of the resulting set is;
> > if X and Y are the graphs arising from
> > the n-triples document jeremy gave as
> > an example, I think the model theory
> > spec depends on the cardinality of {X, Y} being 1.
> >
> > But I'm not certain. It could be that it doesn't
> > matter.
> 
> It doesn't; it's akin to thinking about how many number 10s there are:
> you can take a view, but it's irrelevant to the way you do arithmetic.

You're 100% certain that the RDF semantics document
is indifferent to the cardinality of {X, Y} above?
I'm not (yet) convinced.


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/