- From: Seth Russell <seth@robustai.net>
- Date: Tue, 27 Aug 2002 11:15:43 -0700
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: <sandro@w3.org>, <www-rdf-interest@w3.org>
From: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com> > From: "Seth Russell" <seth@robustai.net> > > > From: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com> > > > > > Well, how does one forbid self-referencing sentences. To do so, one would > > > have to say something like > > > > > > _:s rdf:type rdf:Statement . > > > _:s rdf:subject _:s . > > > > > > is not an RDF graph. > > > > It seems to me that "_:s rdf:subject _:s" is not a self referencing > > triple. In fact I dont's see how you could even write a self referencing > > triple in RDF at all, since RDF does not even provide for triples to have an > > identity. In the example above "_:s" is the identity of the thing of type > > Statement, not the identity of the triple. > > > > Help, I'm confused ? > > > > Seth Russell > > Hmm. You have a point here. You would not have to use RDF reification at all. > > However, suppose you have a way of representing formulae in RDF. This will > have to use resources and statements. When you represention ~p, you will > have to have an RDF graph with a resource for the formula p and another resource > for the formula ~p. How can you allow this, and forbid the RDF graph that > is your RDF graph for ~p except that it replaces the resource for p with > the resource for ~p? I don't understand your paragraph. p is not a formula ... can never be a formula, in my view. Doesn't "p" just identify a node or represent a resource? {p negation ~p} is a formula. I would represent negation, conjunction, and disjuntion formula as per this mentograph: http://robustai.net/mentography/negation_conjunction_disjunction.gif What is the problem again with these kind of arrows ? <snipping stuff who's complexity I do not understand> > Truth and falsity are represented by inclusion in the classes pl:Truth and > pl:Falsity, respectively. Ok, the pink resources (which are formula) can be of of rdf:type pl:Truth or pl:Falsity relative to some other graph. > To forbid self-reference, you have to *forbid* RDF graphs that contain > things like > _:x pl:negation _:x . I have no problem with calling that formula rdf:type pl:Falsity relative to any graph that purports to be binarilay logical. But I dont' know if we must forbid it, I mean anybody can say anything about anything ... can't they? Seth Russell http://robustai.net/sailor/
Received on Tuesday, 27 August 2002 14:16:39 UTC