RE: [TED] Action-188, ISSUE: production rule systems have "difficulty" with recursive rules in RIF Core

	"This would be a ridiculous and unjustified restriction" 
unless CORE is meant to be a common subset of rule language features, in which case it is fully justified. If CORE is a superset of rule language features then there is no need to consider extensions. So what is CORE?

>From http://www.w3.org/2005/rules/wg/wiki/CORE <<... a format that allows rules to be translated between rule languages and thus transferred between rule systems. ... In Phase 1, the RIF Working Group is first defining a CORE Condition Language. These conditions are then used as rule bodies to define a CORE Horn Language. >>
... I take to mean that there no action language in Phase 1, so "computational recursion" is therefore anyway out of scope. 

Paul Vincent
TIBCO - ETG/Business Rules 
 

-----Original Message-----
From: Boley, Harold [mailto:Harold.Boley@nrc-cnrc.gc.ca] 
Sent: 14 December 2006 15:34
To: Michael Kifer; Paul Vincent
Cc: Gary Hallmark; W3C RIF WG
Subject: RE: [TED] Action-188, ISSUE: production rule systems have "difficulty" with recursive rules in RIF Core 

Whether a *specific* Rulebase written in CORE uses recursion/co-recursion
or no recursion, can be found out by a static (dataflow) analysis system.
Keeping the result of this analysis for later use (including for production
rule transformation), e.g. in a 'semantic attribute', is a good example of
Rulebase-level annotations (cf. Roadmap, parts #6 and #9):
http://lists.w3.org/Archives/Public/public-rif-wg/2006Feb/0256.html

-- Harold


-----Original Message-----
From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org] On Behalf Of Michael Kifer
Sent: Thursday, December 14, 2006 10:55 AM
To: Paul Vincent
Cc: Gary Hallmark; W3C RIF WG
Subject: Re: [TED] Action-188, ISSUE: production rule systems have "difficulty" with recursive rules in RIF Core 



This would be a ridiculous and unjustified restriction.

The core is for exchange. There is no requirement for any concrete
system to properly include the core. (Don't confuse concrete systems with
RIF dialects.)


	--michael  

> +1
> Recursion should not be a part of a core rule format (I'm pretty sure recursion is not a feature of constraint rules either).
> 
> Paul Vincent
> TIBCO - ETG/Business Rules 
>  
> -----Original Message-----
> From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org] On Behalf Of Gary Hallmark
> Sent: 13 December 2006 18:39
> To: public-rif-wg@w3.org
> Cc: W3C RIF WG
> Subject: Re: [TED] Action-188, ISSUE: production rule systems have "difficulty" with recursive rules in RIF Core
> 
> 
> 
> 
> Paul Vincent wrote:
> 
> >  
> >
> > Why would you want to define recursion 
> > (http://en.wikipedia.org/wiki/Recursion) in a production rule system?
> >
> >
> Paul,
> 
> As I understand it, RIF Core should be common to *all* RIF dialects, 
> including a production rule dialect.  Now, it's clear that there are 
> aspects of production rules that probably won't translate to Core (e.g. 
> priority, retract).  That may be ok if we can add them to the dialect 
> without breaking the Core semantics.  On the other hand, it is critical 
> that *everything* in Core can be translated to PR, otherwise we have 
> dialects of Core itself, which means it really isn't a Core.  Therefore, 
> if Core supports recursive rules, then so should PR.   If we don't think 
> its practical to support recursive rules in PR, then we should remove 
> this feature from Core.
> 
> Mark,
> 
> I agree that it may be more efficient to add new rete nodes and/or 
> syntax to support recursive rules, but that's not really the point.  The 
> translation from Core to PR should be possible (per our RIF 
> requirements) without having to modify or enhance the production rule 
> engine.
> 
> 
> 
> 
>

Received on Thursday, 14 December 2006 16:40:15 UTC