- From: Francois Bry <bry@ifi.lmu.de>
- Date: Thu, 20 Apr 2006 10:33:03 +0200
- CC: public-rif-wg@w3.org
Dear Gary, > My big concern is finding a single declarative semantics for both > deduction rules and reactive rules. Dop not try. Deduction rules are declarative or stateless, while reactive rules are imperative or state dependent. A common semantics for deduction and reactive rules would as ill-defined a goal as a common semantics for Java and Haskel. A common semantics for deduction and reactive rules would be like marrying fire and water. > Maybe a better way to state this is to have a semantics for RIF that > would let me evaluate a given rule set using either forward chaining > or backward chaining (with the same results obviously). I advocate for a declarative semantics for Horn deduction rules defined in terms of fixpoint and, equivalently, as minimal model. In addition, I advocate for requiring Interpreters of deduction rules to fullfil a few (rewasnable) termination requirements for (syntacxtuically defined) classes of (finite) Horn deduction rule sets > Harold Boley proposed at the last F2F that the rule head would be an > implicit assert when run on a forward chaining engine. That sounded > like a good idea to explore. Might be good for diploma theses or PhD. Leave it gthere. Do not try to marry fire and water. We should not misuse the WG for doing in a few weeks research that has not been done by a much largewr community over a few decades. > Of course, there would be lots of restrictions on the rules, but I > don't see any way to have RIF Core be anything but the semantic > intersection of deductive, normative, and reactive rules. There is a clean and simple way out: RIF been made of 3 complementary yet distiunct languages: a lanfguage of deduction rules, a language of normative rules, and a languiage of reactive rules. Regards, Francois
Received on Thursday, 20 April 2006 08:33:12 UTC