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Re: HTTPS and the Semantic Web

From: Wouter Beek <w.g.j.beek@vu.nl>
Date: Sun, 22 May 2016 09:14:07 +0200
Message-ID: <CAEh2WcNfZPUuv4oRfE0KBUu1KgzKjwhgLOUKha+x9Z8NET_CNg@mail.gmail.com>
To: Henry Story <henry.story@bblfish.net>
CC: nathan <nathan@webr3.org>, Simon Spero <sesuncedu@gmail.com>, Halpin Harry <hhalpin@ibiblio.org>, Carvalho Melvin <melvincarvalho@gmail.com>, "Patrick Hayes" <phayes@ihmc.us>, Archer Phil <phila@w3.org>, Semantic Web IG <semantic-web@w3.org>
Hi Henry,

Thanks for the pointer to POWDER; I was not aware of it yet.

On Sun, May 22, 2016 at 8:23 AM, Henry Story <henry.story@bblfish.net>
wrote:

> I want to point out that a similar issue has already been around for as
> long as the SW exists: IRIs that differ only in terms of escaping are
> different SW names even though they denote the same Web location.  In
> practice I do not always see a data publisher make explicit (`owl:sameAs')
> assertions between [3] and [4] (although some do, I've seen them in LOD
> Laundromat).
>
> I think that equivalence is covered by the URI and IRI spec. URIs have to
> be compared for equivalence after denormalisation, including relative URI
> resolution. ie. <https://www.w3.org/2001/sw/wiki/POWDER> is the same as <
> https://www.w3.org/2002/../2001/sw/wiki/POWDER>.
>

Do you have a reference for the use of denormalization in IRI equivalence
checking in RDF?  IIUC  the current RDF 1.1 specification
<https://www.w3.org/TR/rdf11-concepts/#section-IRIs> takes a different
stance:

IRI equality: Two IRIs are equal if and only if they are equivalent under
Simple String Comparison according to section 5.1
<http://tools.ietf.org/html/rfc3987#section-5.1> of [RFC3987
<https://www.w3.org/TR/rdf11-concepts/#bib-RFC3987>]. Further
normalization *MUST
NOT* be performed when comparing IRIs for equality.

The relation of my remark to the HTTPS discussion is that I can find
empirical evidence in LOD Laundromat that some people are already adding
`owl:sameAs' links between what they consider to be syntactic variations of
the same identifiers.

You are right that HTTP/HTTPS is not a syntactic rewrite of the same
identifier according to the IRI spec, but my point is that
percent-encoded/unencoded is not a syntactic rewrite of the same identifier
according to the RDF spec either.

---
Cheers!,
Wouter.
Received on Sunday, 22 May 2016 07:15:20 UTC

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