- From: McBride, Brian <bwm@hplb.hpl.hp.com>
- Date: Fri, 22 Dec 2000 10:02:55 -0000
- To: 'Bill de hÓra' <dehora@acm.org>
- Cc: "RDF Interest (E-mail)" <www-rdf-interest@w3.org>
Hi Bill, > > My second go at this (I was a bit curt the last time in hindsight, > apologies)... No offense taken :) I support the call for a glossary, and thanks for pointing the ambiguities in my previous posting. If I don't know the ambiguity is there, I can't learn to improve. Happy Holiday's Brian > > : > : Consider a statement S which occurs in two documents, > : > : http://foo and http://bar. > : > : > : > : Let RS be a reified statement representing both S and > : > : its occurrence in http://foo. Thus: > : > : > : > : (occursIn, RS, http://foo) > : > : > : > : is true. > > Unless I missed something, (occursIn, RS, http://foo) is false. There > are an infinite number of resources that might model S, one of which > is RS, according to my understanding of the RDFm. But I don't see how > the presence of a representation of S in a given document > automatically implies the presence of a represention of RS in that > document. That has to be an inference of sorts, or some kind of > normative behaviour allowed to processors. Otherwise, how can one be > sure which of these very many potentially modelling resources of S RS > is the representation of, or should be? If anything, should we have > an infinitely sized alt container hanging off this document > containing all the possible representations of the resources that > model S, where RS is the default? That might be mathematically sound > (I don't know), but it's not useful surely for an implementation. I > have the feeling that the set/math model of RDF such as it is, is > being intertwined with machine dependent implementations. > > > : > If S then your ensuing statement might > : > be true iff RS is present with S in http://foo. > : > : I don't see why. > > It might be, if there is syntactically present an RS that models S in > the document (possibly we need a predicate noReallyOccursIn). > Normally I'd assume a closed world, and say that (occursIn, RS, > http://foo) is false unless that model of S, RS, is > syntactically/literally present. Now, it might be the case that an > RDF processor finds it convenient to automaticaly infer the presence > of RS. But I don't see that in the RDFm (I shall go and check again > though :). > > : > Also, I'm not altogether sure that RS can represent both S and > its > : > occurence. > : > : Neither am I. The message you are responding to was an attempt > : to explain why I don't think it works. > > Ah. My bad. > > > : > Again this is ambiguous. Do you mean an occurence of S > : > within http://foo, or do you mean that RS stands for the > statement S > : > and any occurence/instance of S? > : > : The text I wrote does say "and its occurrence in http://foo". Does > : that not distinguish it from "any occurrence/instance of S"? > > Yes now: I didn't know what "its" was referrring to. > > > : I was feeling today that I at least, made some progress in > : understanding Pierre-Antoine's proposal. The language we used > : was sufficiently precise to clarify differences in our > : conceptions of what is going on here. > : > : However, I feel sufficiently chastised that I'll have a go > : at a more formal approach, something I should have done a > : while ago. > > I feel the same way, but too lazy to get formal (yet). I don't know > whether Pierre's proposal actively causes contradications, but I > don't see how it's generally useful either in processing terms. > Pierre, help? > > - -Bill de hÓra > > -----BEGIN PGP SIGNATURE----- > Version: PGP 7.0 > > iQA/AwUBOkKQguaWiFwg2CH4EQJo8gCfbN5ib8aTyaFasaPC36R7MqqOK8sAoME+ > c7e7Q2vTcAOM7Us0lHxIrLgd > =8XeR > -----END PGP SIGNATURE----- > >
Received on Friday, 22 December 2000 05:04:52 UTC