- From: Francois Bry <bry@ifi.lmu.de>
- Date: Thu, 11 May 2006 10:02:33 +0200
- To: Sandro Hawke <sandro@w3.org>
- CC: Chris Welty <cawelty@frontiernet.net>, public-rif-wg@w3.org
It seems to me that behind the "soundness" discussions, the "semantics" issue is re-emerging. My understandsing is as follows: 1. Interchange of rules and rule sets originally specified after different semantics is needed. Therefore, the possibility of RIF rules and rule sets with different semantics should be a requirement. 2. Such an interchange is only possible if the original semantics of the rules and rule sets to be interchanged is specified. Therefore, the possibility to specify a semantics for a rule or rule set should be a requirement. 3. In most cases, the specification of a semantics for interchange purposes is only possible or meanningfull if this specification is simple enough (ie expressible in a few words, not in ten thousand of lines of code) and abstract enough ("abstract" being understood here as "factoring out some aspects"). As a consequence, simple and abstract specifications of semantics for RIF rules and rule sets should be a requirement. Widespread approaches for sinmple and abstract sapeciofications of semantics for rules and rule sets are as follows: A. for deduction and normative rules: A1. model theories (either Tarskian or non-Tarskian). A2. Proof calculus (without model theories, like eg in constructive logics). B. for production and reactive rules: B1. fixpoint of an immediate consequence function (over rule sets and facts). B2. conflict resolution function (together with fixpoint of an immediate consequence function). 4. The notion of "sound" inferences from RIF rules and rule sets can, and I think should, be defined as: inferences after the specified semantics. Did I miss something? Hopfully, this note will help clarifying issues... François
Received on Thursday, 11 May 2006 08:02:43 UTC