Re: URIs quack like a duck

On Sun, Jun 04, 2000 at 03:51:32PM -0400, John Cowan wrote:
> Clark C. Evans scripsit:
> >  b) an injective identification function is named.
> 
> What about direct assertions?  We can't in practice dereference the
> names "Hesperus" and "Phosphorus" to determine if they identify
> the same thing (because the planet Venus is not a network-retrievable
> resource), nor can we, in the Real World, limit ourselves to just
> one of these names.
> 
> But we can look in a database that informs us that Hesperus is Phosphorus,
> an *a posteriori* truth (it is neither trivial to claim it, nor absurd
> to doubt it).
> 
> So I add to your list:
> 
>    c) metadata informs us that the two URIs name the same resource.

EXACTY!!! This is the case for ALL URIs. The Web only defines
Identifiers and Resources. There is no "great equivalency database
in the sky" to ask. So, unless you have a database handy, you can
only compare two Resources by their Identifiers.

-MM

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Received on Monday, 5 June 2000 10:15:23 UTC