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URI Equivalence?

From: Tony Hammond <tony.hammond@gmail.com>
Date: Tue, 2 Oct 2007 16:11:15 +0100
Message-ID: <c107aff50710020811s6c8bec22t5529c8a423ac51cd@mail.gmail.com>
To: semantic-web@w3.org

I'm curious what can be said in RDF terms re comparing two URIs. For
example, if I have two graphs

    G1: { ns:s ns:p ns:o }
    G2: { ns:s ns:p ns:o }

then what can be said about reconciling the two subjects? Under what
conditions is <ns:s> from G1 identical to <ns:s> from G2, i.e.
referring to the same resource. (I'm assuming full URI normalization
here, i.e. that the two RDF URI references compare equal, character by
character, as Unicode strings.)

So, for example. are there any differences wrt namespace value, e.g.

    a)  @prefix ns: <http://my.example.org/path#> .

    b)  @prefix ns: <data:,> .

>From an RDF pov does it matter that a) has a DNS authority and b) does
not? Or does RDF respect the opaque URI view.

(Of course, both URIs may have representations but that doesn't tell
us much about the resource they reference. The HTTP URI may or may not
have a representation. The DATA URI has an inline representation.)

And then between these two extremes (DNS authority and no authority)
there are those URIs that have a central registry authority.

Glad to get any insights on this question.


Received on Tuesday, 2 October 2007 15:15:25 UTC

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