- From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Date: Mon, 25 Mar 2002 17:47:24 +0000
- To: "Massimo Marchiori" <massimo@w3.org>
- Cc: "Dan Connolly" <connolly@w3.org>, "Pat Hayes" <phayes@ai.uwf.edu>, <w3c-rdfcore-wg@w3.org>, "Lynn AndreaStein" <las@olin.edu>
Massimo, The discussion of whether or not to use Skolemization did come up, at some length as I recall, in our first F2F. The conclusion is reflected (briefly) in the current MT document: http://www.w3.org/TR/rdf-mt/#skolem In particular: [[[ Also, skolemization would not be an appropriate operation when applied to anything other than the antecendent of an entailment. A skolemization of a query would represent a completely different query. ]]] [Pat: I think there's a typo there 'antecendent'->'antecedent'] #g -- At 02:10 PM 3/25/02 +0100, Massimo Marchiori wrote: > > -----Original Message----- > > From: Dan Connolly [mailto:connolly@w3.org] > > Sent: Saturday, March 23, 2002 3:59 AM > > To: Pat Hayes > > Cc: w3c-rdfcore-wg@w3.org; Massimo Marchiori; Lynn AndreaStein > > Subject: motivation for bNodes/existentials in RDF; note for parsers > > > > > > Pat, Dave, > > > > I just explained to another colleague of > > mine, Massimo, that RDF formulas are not > > just sets of ground facts... > > (and > > (p1 s1 o1) > > (p2 s2 "lit2") > > ... > > ) > > > > but that RDF can express existential quantification... > > > > (exists (?b1 ?b2 ?b3 ...) > > (and > > (p1 s1 ?b1) > > (p2 ?b2 "lit2") > > ... > > ) > ><disclaimer> >In these kind of sentences I always have to argue with Dan, as >he always says so and I always reply in the usual way... >So, restating the above, the *current version of the >RDF Model theory* states that the interpretation of RDF >ought to be ... bla. >This is important to remember, as it's a fundamental design choice >that it's going to be decided, but it's not present in the >"normative RDF" (M&S) document. ></disclaimer> > > > Have you added some explanation about that > > to the model theory spec? >I think what concerns me most, in this context, is the appropriate >explanation of why this is the choice to make, versus the most >obvious choice we have at our disposal (i.e., skolemization). >That is, what are the pro's and con's that favour the existential >approach vs the skolem one? >AFAIK the second one has been so far the natural choice (the >"understood standard" if you want ;), for some good reasons. >So, summing up, since this is a fundamental architectural decision >(not just syntactic sugaring) concerning RDF, what is most interesting >is to give the reasons for this interpretation vs the easiest skolem one. >Yes, it's a classic "last call" fundamental question, because that spawns >into the data model, on which there are many things to discuss, but well, >Dan brought the matter up early ;) > >Thanks, >-M > >ps Apologies if the pro-con analysis and motivation has already been posted, >if so I probably missed it (not an unlikely possibility). ------------------- Graham Klyne <GK@NineByNine.org>
Received on Monday, 25 March 2002 13:13:23 UTC