RE: [RIF] Reaction to the proposal by Boley, Kifer et al

Dave, Uli

I understand the requirements for RIF to express, e.g., RDF deduction
directly and Michael's statement does not contradict this. I agree that
having RDF triples in body alone does not suffice.

I appreciate your effort in trying to pin down the issues. Let me
clarify on reaction rules. Reaction rules of event-condition-action
(ECA) type go beyond production rules in several respects. What may be
distinguishing here is that detection of situations may be done based on
various events, not just data changed. Also the action language may
allow for atomic action sequencing including the ability to perform
epistemic and communication actions a minimum. Sequencing may be
critical here because it may be done precisely while production rules
may fire in a different order so the order of actions may not be
predicated in advance. This all calls for actual action language that
may become as powerful as Petri nets or pi-calculus including splits and
joins (see for example, BPEL).

The ability to detect situations in a flexible way and react to
situations in specified patterns may require a special flavor of RIF
that can be annotated appropriately. This may not necessarily contradict
anything, just complement it, as you are suggesting. We are keen to work
on behavioral aspects of RIF and reaction rules in particular.

Alex

-----Original Message-----
From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org]
On Behalf Of Dave Reynolds
Sent: 03 May 2006 16:48
To: Alex Kozlenkov
Cc: public-rif-wg@w3.org
Subject: Re: [RIF] Reaction to the proposal by Boley, Kifer et al


Alex Kozlenkov wrote:

> I am not sending a message against OWL or RDF. I am simply asking
> whether _querying_ RDF and OWL in rule antecedents is enough or not
for
> RIF at this time.

As I've already said in my response to the proposal, external-query-only

is not sufficient from my point of view. I need to be able to express at

least deduction rules over RDF and an external query approach doesn't 
facilitate that. I would prefer a tighter embedding of RDF into RIF 
(e.g. either a three place predicate or the ability to interpret any 
atoms over binary relations as RDF triple patterns).

> Reaction rules may involve a sequence of actions as opposed to one
> action. Semantics of these sequences of actions may be based on
> transaction logic or be even based on process algebras. OWL and RDF
> semantics are likely to be complementary to those.

Complementary is different from incompatible.

What specific problems do production rules raise when processing RDF 
data that don't get raised when processing, for example, XML data?

[I'm not trying to deny there are subtleties there but I am try to pin 
down what specific problems make you unhappy with the more integrated 
approach.]

Dave




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Received on Wednesday, 3 May 2006 16:54:27 UTC