- From: Wouter Beek <w.g.j.beek@vu.nl>
- Date: 2016年5月22日 09:14:07 +0200
- 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>
- Message-ID: <CAEh2WcNfZPUuv4oRfE0KBUu1KgzKjwhgLOUKha+x9Z8NET_CNg@mail.gmail.com>
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