W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > October to December 2011

Re: MS-6 D-Entailment and fixed datatype map

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Sat, 08 Oct 2011 17:57:54 +0100
Message-ID: <4E908112.5030305@epimorphics.com>
To: public-rdf-dawg@w3.org

On 04/10/11 13:39, Birte Glimm wrote:
> Hi all,
> I am working through Michael Schneider's comments and I see two
> possibilities to address
> http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2011Jul/0013.html
> The problem he identifies is that we call the D-entailment regime
> D-entailment, but unlike the D-entailment specification in the RDF
> model theoretic semantics document, we fix a datatype map. Thus, we
> kind of change D-entailment, which is not our business.
> There seem to be two solutions for this:
> 1) Change the name of the regime; Michael suggests XSD-entailment, but
> since we also have rdf:PlainLiteral or rdf:XMLLiteral, I don't find
> that very fitting, so we would have to find a better name.
> 2) We do not specify any concrete datatype map. In this case,
> implementors would have to specify, e.g., in their system
> documentation, what kind of datatypes they support. In this case, we
> also have to think about canonicalisation. For all datatypes in the
> regimes there is a wel-defined canonical form, which has to be used.
> Otherwise, we again have the problem of infinite answers due to
> infinitely many lexical forms for some data values. If we leave the
> choice of the datatype map open, we might have to require that either
> each datatype is such that a canonical form for each data value is
> specified or, for datatypes where this is not the case, implementors
> have to make sure that only finitely many answers are returned and
> describe, e.g., in their system documentation, how that is achieved.
> I tend to prefer option 1 as this is also less likely to require another LC.

Agreed, although a 2LC isn't so bad as we have other documents needing 
to go through 1LC, and some query changes are more honestly handled as a 

As for the name, "XSD-entailment" is OK for me as it's the major part of 
the datatype work, (rdf:XMLLiterals canonicalization is required by 

but if you want a "S-D-entailment" (S = Standard or SPARQL ... not 
serious :)

So the best I can think of at the moment is:


> Birte
Received on Saturday, 8 October 2011 16:58:25 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:01:05 UTC