answers to questions about rdf:text?

From: Pat Hayes <phayes@ihmc.us>
Subject: Re: regrets and last input for the call...
Date: Wed, 27 May 2009 08:57:41 -0500

[...]

> BTW, we now have a new open RDF issue: are rdf:XMLLiteral and  
> rdf:PlainLiteral disjoint?  Is this a new RDF inconsistency:
> 
> _:x rdf:type rdf:PlainLiteral .
> _:x rdf:type rdf:XMLLIteral .
> 
> I can see arguments both ways, but I think we ought to decide it and  
> give a ruling, rather than just let the matter dangle so that people  
> will do it various ways. It seems more useful to say they are  
> disjoint, even though valid XML is still perfectly correct as a  
> character string. And Ive heard it argued that marked-up text is still  
> not plain text, even when it has no markup. I guess it kind of smells  
> different, or something.

I think that this is adequately addressed by the wording in RDF
Concepts,  

  The value space [of rdf:XMLLiteral]
  is a set of entities, called XML values, which is:
  * disjoint from the lexical space;
  * disjoint from the value space of any XML schema datatype [XML-SCHEMA2];
  * disjoint from the set of Unicode character strings [UNICODE] strings;
  * and in 1:1 correspondence with the lexical space.

This does not exactly rule out that some elements of the value space of
rdf:XMLLiteral could be pairs of strings and language tags, but I think
that this would go without saying.

> Another question: do we want to provide a way **in RDF** to talk about  
> the lang tags directly? That is, should the extension provide for RDF  
> properties to support entailments like these:
> 
> aaa ppp "this"@that .
> 
> ??entails??
> 
> aaa ppp _:x  .
> _:x rdf:hasString "this"  .
> _:x rdf:hasTag  "that"  .
> 
> The reason I ask is, if people think this might be useful (seems to me  
> it would be) then now is surely the time to define them, as part of  
> the overall convention.
> 
> No doubt their names should be chosen better, but Im sure y'all see  
> the point.

I would say that we don't need to go there, and in the interests of time
that we shouldn't.

> Pat

peter

Received on Wednesday, 27 May 2009 16:52:05 UTC