- From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
- Date: Wed, 14 Nov 2012 15:48:27 +0100
- To: public-rdf-wg@w3.org
Le 14/11/2012 11:19, Pierre-Antoine Champin a écrit : > Pat, > > On Wed, Nov 14, 2012 at 8:16 AM, Pat Hayes<phayes@ihmc.us> wrote: > >> What I still don't follow is, why anyone who understands what an >> inconsistency is, would even form the idea that an ill-typed literal would >> be an inconsistency. It's not the distinction that needs explaining, it's >> why anyone would treat them as similar in the first place. Illformedness >> is not even in the same category as an inconsistency. Literals aren't true >> or false by themselves. >> > > I think the divergence of opinion comes from the fact that > > * you see typed literals merely as terms (which, strictly speaking, they > are), and a term can not be False; it just denotes something ; > > * others (at least myself!) see a little more in them, namely: an implicit > assertion that the denoted thing is indeed in the value space of the > datatype. > > If we decide to bite that bullet, then this could be endorsed in the > semantic condition for a *graph*: > > if E is a ground RDF graph then I(E) = false if I(E') = false for some > triple E' in E, > or if I(E') is not in LV for some typed literal E' in V, > otherwise I(E) =true. Ouch. I don't like the fact that the notion of type comes in at the level of ground-graph simple entailment. The more I think of this issue, the more I believe that ill-typed literals should be a syntax error. An application that supports a datatype should reject RDF graphs that do not write literals of that type properly. Note that in OWL 2 Structural Specification and Functional Style Syntax, it is required that: "The lexical form of each literal occurring in an OWL 2 DL ontology MUST belong to the lexical space of the literal's datatype." cf. Section 5.7 http://www.w3.org/TR/owl2-syntax/#Literals. AZ > The first line (from the original definition) accounts for everything > asserted explicitly in a triple, > while the second line (which I added) accounts for those "implicit" > assertions carried by typed literals. > > Do you think it's a clean way to do it? Or do you consider it as just > another "trick" ? :-) > > pa > -- 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 Wednesday, 14 November 2012 14:48:51 UTC