- From: Bijan Parsia <bparsia@isr.umd.edu>
- Date: Mon, 13 Mar 2006 05:02:11 -0500
- To: "Gerd Wagner" <wagnerg@tu-cottbus.de>
- Cc: <public-rif-wg@w3.org>, "'Sandro Hawke'" <sandro@w3.org>
On Mar 13, 2006, at 4:33 AM, Gerd Wagner wrote: >> My understanding is that derivation rules and integrity >> constraints are >> just a bifurcation of Horn rules (or sometimes the two halves of >> something beyond Horn). As such they fit easily into the same >> semantics. > > Not really, there are both syntactic and semantic > differences: > > - derivation rules, in general, correspond to Gentzen > sequents; [snip] > - integrity constraints, in general, correspond to > sentences of some logic (which may be classical FOL, > temporal FOL or some modal FOL); as emphasized by > SBVR, [snip] > Given all these differences, how can you say "they > fit easily into the same semantics"? While I wouldn't have said it the way Sandro did, there are attempts to formalize integrity constraints (with all their semantics and pragmatics) using the K and A operators (i.e., in MKNF): http://citeseer.ist.psu.edu/237686.html http://www.cs.utexas.edu/users/vl/mypapers/mbnf.ps (Of course, using K & A is a little like using continuations to model threads and exceptions....you can do it, and it's cool, but, uh, it's generally harder than direct approaches.) > The fact that, in certain circumstances, they may both > take the form of a Horn formula does not mean they > have the same semantics [snip] That I *heartily* agree with. Cheers, Bijan.
Received on Monday, 13 March 2006 10:02:23 UTC