- From: Michael Kifer <kifer@cs.sunysb.edu>
- Date: Wed, 01 Feb 2006 15:03:06 -0500
- To: Francois Bry <bry@ifi.lmu.de>
- Cc: "Ginsberg, Allen" <AGINSBERG@imc.mitre.org>, public-rif-wg@w3.org
Francois Bry <bry@ifi.lmu.de> wrote: > > I agree that RIF should have (1) a clear declarative semantics and (2) > in addition support conveying *some* *limited* specifications of > procedural semantics (eg backward chaining is intended because with > forward chaining the considered rules would require to process all/too > many nodes on the Web). I disagree with that, especially with the statement that "with forward chaining the considered rules would require to process all/too many nodes on the Web". This is all a matter for the query optimizer to resolve. > Back to RIF: I beleive RIF should give rise to express: > > - logical formulas in a FOL style (preferably using a rich syntax) > - intended use of the formulas (eg deduction rule, integrity > constraints, ontologies) > - intended negation (monotonic or non-monotonic) > - intended declarative semantics (eg Well Founded or Stable Model or FOL) > - intended truth valuations of all kinds (including discrete truth > valuations such as eg true/false, true/unknown/false, > known-tue/possibly-true/possibly-false/known-false as well as continous > truth valuations such as [0..1] 0 meaining false, etc.) > - schemas (in the acception of RDFS) ie what is also called sorts in > automated reasoning and logic (ie classes and sub-class relationships > and the like) > - name (not procedural semantics!) of the rule engine the rules have > been designed for. > - maybe further "properties". > > Of course, RIF should make it possible that some of the above is not > specified with a ruleset. Amen to that (although I am not sure that we will want to handle all of that in the end). --michael
Received on Wednesday, 1 February 2006 20:03:42 UTC