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Contradicting definitions of “property”

From: Richard Cyganiak <richard@cyganiak.de>
Date: Thu, 26 Apr 2012 01:00:30 +0100
Message-Id: <99805751-F13F-48B8-993E-9F6093242769@cyganiak.de>
Cc: Simon Reinhardt <simon.reinhardt@koeln.de>
To: RDF Working Group WG <public-rdf-wg@w3.org>
All,

Simon Reinhardt spotted [1] a nice little contradiction between the 2004 versions of RDF Concepts and RDF Semantics.

RDF Concepts states, in a normative section [2]:

[[
The predicate is also known as the property of the triple.
]]

Where “predicate” is defined as a URIref, one of the three components of a triple. RDF Semantics, on the other hand, defines [3]:

[[
A simple interpretation I of a vocabulary V is defined by … a set IP, called the set of properties of I.
]]

And the rest of the mechanics make it clear that URIrefs can denote a member of IP. In other words, RDF Concepts says that the predicate IRI *is* the property, while RDF Semantics says that it *denotes* the property.

The analogy with classes shows IMO that RDF Concepts is wrong and RDF Semantics is right. The IRI <http://xmlns.com/foaf/0.1/Person> *is* not a class, but it *denotes* a class.

I therefore deleted the normative definition quoted above from the RDF Concepts ED. If you disagree with this change or see further need to discuss this, then please respond.

Note that the new Introduction section in the RDF Concepts ED contains an *informative* sentence that introduces the term “property” [4], and it is in line with RDF Semantics:

[[
The predicate itself is an IRI and denotes a binary relation, also known as a property.
]]

Best,
Richard


[1] http://lists.w3.org/Archives/Public/public-rdf-comments/2012Mar/0008.html
[2] http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#section-triples
[3] http://www.w3.org/TR/2004/REC-rdf-mt-20040210/#gddenot
[4] http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#dfn-property
Received on Thursday, 26 April 2012 00:01:00 UTC

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