- From: Jonathan Borden <jborden@mediaone.net>
- Date: Mon, 4 Jun 2001 12:47:29 -0400
- To: "Wolfram Conen" <conen@gmx.de>
- Cc: <www-rdf-logic@w3.org>
Wolfram Conen wrote: > Jonathan Borden wrote: > > > > The problem is the term 'ground fact' and the way it is equated with the > > simple _presence_ of a triple in RDF. In so doing, RDF uses up what a _fact_ > > is. For example, a new language or an extension of RDF might wish to equate > > a fact with an expression constructed of multiple triples e.g. a subgraph. > > But RDF does not allow the assertion of a subgraph without asserting every > > triple in the subgraph. > > That seems to be true, but the questions are how you "express" what you > want to model and how you "interpret" (in the sense of giving it a > menaing in a universe of discourse) the resulting graph (is this > prescribed in RDF?). Let me be more specific along your example: > > > > > Hence what should be a simple construct: > > > > (not (color sky blue)) > > > > becomes contorted. > > Yes, if you model this as (for example): > > [sky color blue] > [r type statement][r subject sky][r predicate color][r object blue] > [r hasTruthvalue not] > > it becomes a little bit diffult* (see additional remark below, if you > like). Not just "difficult", I would say this is a logical contradiction. Removing the [sky color blue] triple makes it merely contorted (i.e. 5 triples for 2 statements) and suppose we then apply "not" to the entire expression, we cannot reconstitute the supposed 'fact' [sky color blue] without 'unreifying' the group of 4 statements. The usual rules of a not applied to a not would be to simply remove the not e.g. (not (not s)) => s, but (not (not s)) where s is a reified statement implied the reified statement - no? regardless this seems contorted at best. -Jonathan
Received on Monday, 4 June 2001 13:05:46 UTC