- From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Date: Fri, 16 Nov 2001 11:37:32 +0000
- To: Pat Hayes <phayes@ai.uwf.edu>
- Cc: w3c-rdfcore-wg@w3.org
It's almost a victim of its own beauty ;-) I completely overlooked the section of graph merging when I responded, partly because it was so short but mostly because I wasn't expecting it to be in the section on entailment... (That's not much of an excuse really, it is well-enough signposted in the document; oh well.) Anyway, a simpler suggestion might be to simply move the definition of graph merging up to section 0.2, just after the definition of tidiness? #g -- At 04:35 PM 11/15/01 -0600, Pat Hayes wrote: >>At 09:03 AM 11/15/01 -0600, Dan Connolly wrote: >>>No? Why not? How is it that you conclude that bnodes >>>in different graphs are different? I don't see it stated >>>in the model theory. >> >>It appears it's not stated directly, and probably should be since that >>was (to me) clearly the intent of our discussions. Also, the final >>sentence of this text from section 2.0 pretty clearly signals that intent: >> >>[[[ >>This effectively treats all unlabeled nodes as existentially >>quantified in the RDF graph in which they occur. Notice that since >>two nodes cannot have the same label, there is no need to specify >>the 'scope' of the quantifier within a graph. (However, it >>is local to the graph.) If we were to apply the semantics >>directly to N-Triples syntax, we would need to indicate the >>quantifier scope, since in this lexicalization syntax the same bNode >>identifier may occur several times. The above rule amounts to >>the N-triple convention that would place the quantifiers just >>outside, i.e. at the outer edge of, the N-triple document >>corresponding to the graph. >>]]] > >The reason why this issue is treated rather elliptically in the MT is that >the great merit of the graph syntax, as I see it, is that the issue simply >*does not come up*. There are no quantifiers, no bound variables and no >scopes to keep track of, it all works out automatically. The merging >conditions are a joy to state (merge nodes required to be tidy, ie >urirefs; don't merge anything else.) It's beautiful. It seemed perverse to >introduce the clunky logical notation only to be able to say that we don't >have those problems. > >If people feel that this issue should be aired more thoroughly, I would >suggest that I write a slightly fuller account of how the graph syntax >makes local scoping unnecessary, maybe with a couple of examples, and put >it into the 'mapping into logic' section, and then refer to that from >elsewhere in the document as needed. Any objections/comments? > >Pat > >-- >--------------------------------------------------------------------- >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 ------------------------------------------------------------ Graham Klyne MIMEsweeper Group Strategic Research <http://www.mimesweeper.com> <Graham.Klyne@MIMEsweeper.com> __ /\ \ / \ \ / /\ \ \ / / /\ \ \ / / /__\_\ \ / / /________\ \/___________/
Received on Friday, 16 November 2001 07:36:33 UTC