(kinda urgent) cheap solution to XML Literals problem...

I'm trying to understand and be able to explain why the Last Call
design for XML Literals doesn't work.   But I just don't see it.

Jeremy gave an apparent paradox [1], but it seems to me to be based on
the faulty assumption that any unknown datatype is distinct from
rdf:XMLLiteral.

That is, 

(1)    <eg:a> <eg:p> "foo"@en^^<eg:d> .

does NOT entail

(2)    <eg:a> <eg:p> "foo"@fr^^<eg:d> .

where he said it did.

I would say that

(3a)   <eg:a> <eg:p> "foo"@en^^<eg:d> .
(3b)   <eg:d> owl:differentFrom <rdf:XMLLiteral>.

does entail (2)

Of course that entailment only holds in OWL Full, but the spirit of it
-- that its valid to infer (2) only if you somehow know the datatype
is distinct from rdf:XMLLiteral -- makes perfect sense in simple RDF.

I don't see anything counter-intuitive or problematic here.  When
reasoning about datatypes about which one has no knowledge, one will
not be able to naively discard language tagging, but I really don't
see the problem with that.

Personally, I would rather see rdf:XMLLiteral be considered one
instance of a class of language-sensitive datatypes, so that instead
of (3b) we'd have something like
 
(4b)   <eg:d> rdf:type <rdf:LanguageInsensitiveDatatype>.

which would be a part of the theory for <eg:d>.   The theory for
rdf:XMLLiteral would of course say it was an instance of 
rdf:LanguageSensitiveDatatype. 

Do either of these designs work for you?  The first has the tremendous
advantage of differing from the Last Call semantics only as much as
needed to fix the error.  The second is perhaps a greater change, but
it's hard to imagine anyone objecting, and it avoids the potential
disaster of someday finding another language-sensitive datatype.

     -- sandro


[1] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Apr/0314.html

Received on Wednesday, 13 August 2003 15:13:04 UTC