- From: Graham Klyne <Graham.Klyne@Baltimore.com>
- Date: Wed, 25 Jul 2001 15:51:14 +0100
- To: pat hayes <phayes@ai.uwf.edu>
- Cc: Brian McBride <bwm@hplb.hpl.hp.com>, w3c-rdfcore-wg@w3.org
At 10:15 PM 7/23/01 -0700, pat hayes wrote:
>It isnt clear to me what the scope of anonymous node is intended to be,
>but it if it is the document containing the node, then indeed it should be
>impossible for any other source to say anything about the thing it refers
>to, so this is a genuine difference. However, the same is true of a
>non-anonymous URI if its use is restricted to this one source.
I've been thinking recently about encoding inference rules in RDF, where a
rule may have a variable that is scoped by the rule; e.g.
Dog(?x) -> Animal(?x)
Originally, I was thinking that, when encoding this in RDF the variable
represented by ?x must somehow be scoped within the RDF. But when I
started looking at candidate RDF encodings this need for scoping just melts
away: the variable is represented by a new, unique resource: that
resource has global scope (and, hence, if it has a URI it is one that is
not shared by any other resource). The only place where the concept of
scope is needed is in the original expression. Some other expression; e.g.
Cat(?x) -> Animal(?x)
Has a different scope for its ?x, but the resource that represents the
variable in the encoding of this is a different resource than the one that
represents ?x in the previous example.
From this exercise, I tentatively suggest that the scope of any resource
(node) is global -- the entire universe of discourse.
(I'm trying to be clear that this is an encoding of inference rules in RDF,
not an attempt to make inference rules part of RDF.)
#g
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Graham Klyne Baltimore Technologies
Strategic Research Content Security Group
<Graham.Klyne@Baltimore.com> <http://www.mimesweeper.com>
<http://www.baltimore.com>
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Received on Wednesday, 25 July 2001 12:22:05 UTC