Re: namespace usage as assertions

Rick JELLIFFE wrote:

<digression>
> In typical computer languages, we are used to a left-hand side and a
> right-hand-side of an assigment or equation operator. There is a name on
> the left, and an evaluatable value on the right (unless you are using
> BLISS).

Even in Bliss; it's just that "foo" means the same thing everywhere (a name),
and one must write ".foo" to get its value.  Not so different from
shell scripts, BTW.
</digression>

> If URIs could be explained in terms where "resource" does not
> seem to sometimes be used for the LHS (the identifier?) sometimes for
> the LHS (the entity?) and sometimes for the = (retrieval semantics?
> referencing semantics?)  I am sure many people would find it helpful.

A resource is neither a URI nor an entity: it is an abstraction, named by a URI,
and which is concretely represented by one or more entities.

> The thing I find difficult is that "resource" seems to mean "anything
> that has a URI"

Just so.

> If the only property that brings a resource into being is having a name,
> then why make the distinction between (absolute) names and resources?

Because it may be the case (though some deny it) that a single resource has
more than one URI.  On that view, there is no way of determining whether two
URIs refer to the same resource or not, save by asking the resource owner
(who may publish the fact in RDF or otherwise).  Attempting to retrieve
the entities and comparing them is neither necessary nor sufficient. 

-- 

Schlingt dreifach einen Kreis um dies! || John Cowan <jcowan@reutershealth.com>
Schliesst euer Aug vor heiliger Schau,  || http://www.reutershealth.com
Denn er genoss vom Honig-Tau,           || http://www.ccil.org/~cowan
Und trank die Milch vom Paradies.            -- Coleridge (tr. Politzer)

Received on Wednesday, 21 June 2000 16:08:14 UTC