- From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
- Date: Thu, 23 Aug 2012 12:12:11 +0200
- To: Richard Cyganiak <richard@cyganiak.de>
- CC: RDF Working Group WG <public-rdf-wg@w3.org>, Simon Reinhardt <simon.reinhardt@koeln.de>
Le 22/08/2012 23:58, Richard Cyganiak a écrit : > On 13 Aug 2012, at 18:29, Antoine Zimmermann wrote: >>> 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. ]] >> >> This is not what the RDF semantics says. A predicate denotes a >> resource that must be in IP, the set of properties in the >> interpretation. Resources in IP are associated with a binary >> relation via the extension function IEXT. This is an important >> distinction since this is what allows RDF to talk about properties, >> classes, etc as instances. > > Ah, right. I forgot about the class/property extension stuff in RDF > Semantics. > >> If predicates were denoting binary relations, the following would >> be RDFS-inconsistent, when it is, in fact, RDFS-consistent: >> >> :p rdf:type xsd:string . :s :p :o . > > Do I get this right? This would be inconsistent because the first > triple says its a Unicode string, and the second triple entails that > it is a property, and hence (if my phrasing above were indeed > correct) a binary relation. And a Unicode string is not a binary > relation. > > And in reality, as RDF Semantics defines things, the second triple > only entails that the Unicode string *has a property extension*, and > the property extension is a binary relation. Hence, no contradiction. > Anything can have a property extension. > > Right? Yes. > >> This is a proposal to replace the wording in section 1.2 [1]: >> >> "The predicate itself is an IRI and denotes a property, that is, a >> resource that defines a binary relation." > > As usual, given that this is informative introduction text, there is > a balance to be found between accuracy and simplicity. So I'd like to > toss this around a bit. If it is informative, then I don't object, but isn't my proposal rather simple? > Is it accurate to say that the resource "defines" a binary relation? > In what sense does it do that? I'll use your argument: I could not find better without being overly complicated. It's informative, you know ;) > Wouldn't it be slightly more accurate (but perhaps less > understandable) to say that the predicate IRI denotes "a property, > that is, a resource that can be interpreted as a binary relation"? The problem is that "denotes" is a synonym of "is interpreted as", formally. > > How about the fuzzy but perhaps simpler: "The predicate IRI denotes a > property, that is, a resource that can be thought of as a binary > relation." I like this one. > Or: "The predicate IRI denotes a property, that is, a resource that > can be formalized as a binary relation." > > I note that the overall purpose of the sentence is just to introduce > the term "property" and give readers a decent intuition of what the > term means. From that point of view, I still quite like the current > phrasing ("The predicate IRI denotes a binary relation, also known as > a property.") even though I know it's technically inaccurate. May I > claim "harmless abuse of terminology" here? I'd prefer "The predicate IRI denotes a property, that is, a resource that can be thought of as a binary relation." But I won't open an ISSUE for that. > > Best, Richard > > >> [1] 1.2 Resources and Statements. >> http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#resources-and-statements > >> -- Antoine Zimmermann ISCOD / LSTI - Institut Henri Fayol École Nationale Supérieure des Mines de Saint-Étienne 158 cours Fauriel 42023 Saint-Étienne Cedex 2 France Tél:+33(0)4 77 42 66 03 Fax:+33(0)4 77 42 66 66 http://zimmer.aprilfoolsreview.com/
Received on Thursday, 23 August 2012 10:12:44 UTC