- From: Bill Andersen <andersen@ontologyworks.com>
- Date: Thu, 23 May 2002 15:44:35 -0500
- To: "R.V.Guha" <guha@guha.com>, Jeff Heflin <heflin@cse.lehigh.edu>, RDF Logic <www-rdf-logic@w3.org>
On 5/23/02 13:29, "R.V.Guha" <guha@guha.com> wrote: > [to Jeff Heflin] > > About the issue of RDF & RDFS being hard to extend --- let us be > *very* clear on this. RDF & RDFS were designed to be Cyc like systems > [1]. They were *not* designed to be DL like systems. You are finding it > hard to reconcile the two. Cyc-like systems are extensible and have been > extended, though not in a fashion that is consistent with DL > model-theories. Yes, the clothes don't fit the person. Maybe the > problem is with the clothes and not the person. Hi all.. It's unclear what Cyc's model theory is at all. So if you pick some model theory T, it's a fair bet that Cyc's model theory, whatever it is, is inconsistent with T. At it's base, the Cyc engine is a resolution theorem prover augmented with special purpose modules (many of which have fixpoint semantics) and the argumentation system for NM reasoning, so you have some minimal model stuff thrown in. I would defy anyone, even including Keith Goolsbey who wrote the thing, to tell me what all of that *combined* means. In my view, this is nothing to crow about. Cyc is an amazing system - it does lots of incredible things. But what is unclear is what it doesn't do or what it gets wrong, or how long it takes to do some given inference, etc. All of which are undesirable properties, IMHO, for the Semantic Web. When I go to Google, I have some reasonable expectation that what its crawler has seen, I will find, assuming I use the right terms. I would like something of the same assurance with the Semantic Web and I wouldn't bank on a Cyc-like system giving that to me. .bill
Received on Thursday, 23 May 2002 16:44:43 UTC