Re: DAML ObjectProp vs DatatypeProp

   From: "Jonathan Borden" <jborden@mediaone.net>

   The SGML/XML tradition _firmly_ is to represent textual data, character
   encodings etc. You will find very little ... or nothing ... assigning
   _meaning_ to character tokens such as "true" and "false". The SGML/XML
   tradition is to make a sharp and unequivocal distinction on these matters,
   _specifically_ so as not to cause the sorts of problems you identify.

   Understanding this, and if you are prepared to assign such semantics
   yourself, you might find it a pleasure to work with (it won't step on your
   toes in this regard either).

Thanks.  This clears up a significant amount of my confusion.

From the point of view of RDF/DAML, I think we can conclude:

 - The XML 1.0 spec defines the syntax
 - The XML Schema Datatypes spec defines the syntax and semantics of
     (nonstring) literals
 - String literals are a bit messed up but we can work around the
     glitches for those occasions when we really need them.
 - RDF/DAML stacks a layer of denotational semantics on top of
     SGML/XML, and for the first time addresses the semantics of names
     (including property and class names).

As far as the last point goes, my impression is that RDF and DAML have
tried the daring move of using URIs to solve all the problems of name
semantics at one blow.  I don't think they succeed, but too much has
been said about this topic recently anyway.

                                             -- Drew McDermott

Received on Thursday, 17 May 2001 14:15:41 UTC