RE: A summary of the proposal for resolving the issues with rdf:text --> Could you please check it one more time?

Hello,

[snip]

> OWL 2 and RIF accept, in their RDF transcriptions, RDF plain literals
> using the current RDF syntax without change; but treat them, for
> internal purposes, as 'invisibly' typed by a datatype which I will
> here call foo:text. This foo:text is unique among RDF datatypes in
> that it can apply to literals with language tags. The lexical space of
> foo:text is the set of all strings and pairs <string, tag>, and its
> L2V mapping is the identity map. (Or, if y'all prefer, it could be
> restricted to the case with tags, and just use xsd:string for the
> untagged case.)
> 

Before I voice my objections to this solution, I would like to point out
something that probably should have been mentioned in the discussion thus far,
and which, I believe, renders the compatibility argument moot: OWL 2 Full works
with plain literals AS THEY ARE. That is, in OWL 2 Full -- which is built
directly on top of RDF syntax and semantics -- plain RDF literals exist in
exactly the same form as they exist in RDF: no changes, no special cases, no
nothing. Thus, if you are purely in the RDF world, nothing changes.


It is only in the structural specification of OWL 2 and RIF that the
compatibility argument might potentially apply. Both of these specifications
have their independent conceptual models and, to enable interoperability with
RDF, they provide RDF import/export functionality. But precisely because the
conceptual models of these specifications are not layered on top of RDF, the
compatibility argument does not apply to them. At best, the compatibility
argument can be applied to the RDF import/export features of these
specifications.


Now as to the above solution, I think it is not viable simply because, in XML
Schema, the lexical space of any datatype (and rdf:text is going to be a
datatype just like any other XML Schema datatype) is a set of strings; thus, it
cannot be a set of pairs. Introducing yet another exception is unacceptable, as
this would cause major disruptions of various definitions in the structural
specifications of OWL 2 and RIF.


The best compromise we can come up with is to keep rdf:text as is, but place
restrictions on the cases when OWL 2 ontologies and RIF rule sets are written
into RDF. These already exist in the structural specification of OWL 2 (see
Section 5.7 of the Syntax document). Therefore, I strongly believe we are simply
in good shape to close this discussion.

[snip]

Boris

Received on Thursday, 21 May 2009 17:17:36 UTC