- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Fri, 16 Nov 2001 11:35:11 -0600
- To: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Cc: w3c-rdfcore-wg@w3.org
>It's almost a victim of its own beauty ;-) We will soon be talking about candles in the wind if we go on like this. >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? Yes, I like that idea. Put all the graph manipulating stuff into one place, then later on explain what it means. I'll try doing that; but not in the next-week version; since until we get the datatyping sorted out, its not clear what notion of 'tidiness' is appropriate, and I want to just slip past that issue at present. Pat >#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> > __ > /\ \ > / \ \ > / /\ \ \ > / / /\ \ \ > / / /__\_\ \ >/ / /________\ >\/___________/ -- --------------------------------------------------------------------- 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 Friday, 16 November 2001 12:36:16 UTC