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RE: Question re: URIs

From: Graham Klyne <GK@ninebynine.org>
Date: Mon, 08 Sep 2003 11:30:56 +0100
Message-Id: <>
To: Larry Masinter <LMM@acm.org>, "'Sandro Hawke'" <sandro@w3.org>
Cc: uri@w3.org

The formal semantics for RDF talks about there being a *set* of resources.

To define a set, there needs to be some notion of equality, or sameness, 
which I would assume to be the notion used in talking about one-to-one or 

Of course, this line is applicable only to a semantic web viewpoint, I 
guess others might vary.  Do we mean for resources to be set theoretic in 


At 21:10 07/09/03 -0700, Larry Masinter wrote:

>Re: Many-to-One vs  One-to-One
>I think the question is ill-formed; it assumes that
>the space of resources has a well defined equality
>Before you can ask if there are two URIs U1 and U2 such
>that U1 != U2 but
>ResourceIdentifiedBy(U1) == ResourceIdentifiedBy(U2)
>you have to know what '==' means for resources. But
>there is no well-defined equality for resources, so
>the question doesn't make sense.
>many-to-one and one-to-one only apply to spaces with
>well-defined (and, for that matter, unique) equality

Graham Klyne
Received on Monday, 8 September 2003 06:50:38 UTC

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