- From: pat hayes <phayes@ai.uwf.edu>
- Date: Tue, 19 Jun 2001 12:28:52 -0500
- To: Brian McBride <bwm@hplb.hpl.hp.com>
- Cc: Drew McDermott <drew.mcdermott@yale.edu>, www-rdf-logic@w3.org
>pat hayes wrote: > > Seems to me that > > introducing contexts or quads or whatever are all much bigger changes > > to the RDF model than introducing what amounts to a new category of > > triple (or just changing the spec so that some of the old triples > > have a different interpretation.) > > >M&S discusses the concept of a 'model' or 'graph' aka context >aka StatementSet - essentially being a set of statements. Unfortunately >it doesn't make any mention of this concept in the section 5. > >Thus this concept does not have to be introduced to RDF, but it does >need to be better defined. I took it that the 'graph' described in M&S was not an entity, but a way of thinking about RDF as a whole. A kind of graphical abstract syntax for the entire language, rather than a syntactic construct. >For my money a lump of RDF/XML or N3 represents a set of Statements and >we can talk about whether a statement is a member of that set or not, >something I find clearer than talking about whether a statement is >'asserted' or not. The issue however is whether these sets can themselves be incorporated into sentences. Adding that ability changes the language profoundly. BTW, a problem with the above (for me) is that when used in the ways I want to use them, many of the triples inside such a set are not statements - they don't have truthvalues or express a proposition. Maybe this is just a terminological quibble, but it does have a nonterminological consequence when trying to define a coherent semantics, because we need a way to distinguish the 'real' statements from the mere parts of other, larger, statements. >N3 introduces a syntax for embedding the respresention of such a set >of statements (N3 calls them contexts) inside the representation of another, >a feature RDF/XML current lacks. Well, sorry again to quibble, but N3 didnt *introduce* such a syntax. If anyone did, it was probably one of Peirce, Frege or Aristotle, although one could make a pretty good case that it was the first proto-human who ever thought of writing down speech, probably in ancient Sumeria. BTW, I have yet to discover what exactly a 'context' is in N3. Is N3 supposed to be syntactic sugar for a particular way of writing RDF, or is it a different language altogether? Pat Hayes --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Tuesday, 19 June 2001 13:28:55 UTC