- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Thu, 10 Nov 2011 17:43:49 +0000
- To: Alex Hall <alexhall@revelytix.com>
- Cc: Antoine Zimmermann <antoine.zimmermann@emse.fr>, public-rdf-wg@w3.org
Alex, On 10 Nov 2011, at 16:33, Alex Hall wrote: > That's almost exactly what RDF Semantics 2004 says: "Typed literals whose type is not in the datatype map of the interpretation are treated as before, i.e. as denoting some unknown thing." (Section 5.1) Oh, I thought I carefully read all of Section 5 but had missed that sentence. That addresses the situation indeed. I note the following sentence: [[ The condition does not require that the URI reference in the typed literal be the same as the associated URI reference of thedatatype; this allows semantic extensions which can express identity conditions on URI references to draw appropriate conclusions. ]] So if the graph contains "xxx"^^<not-a-datatype>, then the literal might still acquire a value because <not-a-datatype> might be owl:sameAs xsd:string, but not in any of the standard RDF entailment regimes. So the formally correct thing to say would NOT be: The value of a literal whose datatype IRI is not in the datatype map is unknown. but: The value of a literal whose datatype IRI does not denote a datatype in the datatype map is unknown. Oh well. > I would prefer to have literals of type rdf:LangString denote themselves in all interpretations rather than some unknown thing, but I don't know how best to make it happen. Clearly it can't be done through the L2V mechanism. That's easy a new row in the first table in Section 1.4: http://www.w3.org/TR/rdf-mt/#gddenot If E is a language-tagged string with lexical form aaa and language tag ttt in V then I(E) = <aaa,ttt> and appropriate exceptions have to be stated in some places that talk about datatype IRIs if the datatype IRI is not rdf:langString, then Best, Richard
Received on Thursday, 10 November 2011 17:44:19 UTC