In-Reply-To: <20061217173707.DAA2D4F13A@homer.w3.org>
References: <18879.1166375483@cs.sunysb.edu> <20061217173707.DAA2D4F13A@homer.w3.org>
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Cc: kifer@cs.sunysb.edu (Michael Kifer), Paul Vincent <pvincent@tibco.com>,
        Gary Hallmark <gary.hallmark@oracle.com>,
        W3C RIF WG <public-rif-wg@w3.org>
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From: Francis McCabe <frankmccabe@mac.com>
Subject: Re: [TED] Action-188, ISSUE: production rule systems have "difficulty" with recursive rules in RIF Core
Date: Sun, 17 Dec 2006 09:44:22 -0800
To: Sandro Hawke <sandro@w3.org>

Well, if the purpose of the RIF is to have a language that represents  
the intersection of all rule languages, as opposed to being a means  
of interchange between rule systems, then you would be right. But I  
am strongly of the view that the intersection of all rule languages  
is empty.

On the other hand, a different form of conformance would be that any  
given rule language should be able to express their rules in the RIF.  
That does not require all rule language engines to be able to  
understand all elements of the core.

Frank


On Dec 17, 2006, at 9:36 AM, Sandro Hawke wrote:

>
>
>>> Some guidance about writing conformance clauses (which I'll re- 
>>> read now)
>>> is at http://www.w3.org/TR/qaframe-spec/ .
>>
>> I am not concerned with conformance clauses right now, but rather  
>> with
>> defining what might be a reasonable set of features (for lack of a  
>> better
>> word) that should allow us to call something a core or a dialect  
>> extending
>> the core.
>
> I think the difference in what we are talking about is in the
> conformance clause -- that's why I want to focus there.
>
> I think RIF's conformance clause will say that for a rule system to
> implement RIF it has to handle all RIF Core.
>
> Do you want to force all rule systems to handle full recursive  
> Horn?  If
> RIF tries to do that, I think a lot of rule system vendors will  
> tell us
> "no" and not adopt RIF.  It seems to set the bar too high.
>
> The fact that non-recursive Horn is too high a bar for non-rule  
> database
> vendors is okay, since this is RIF not DBIF.
>
>     -- Sandro
>