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

On Dec 17, 2006, at 11:39 PM, Sandro Hawke wrote:
[snip]
> I usually hear this kind of "standard subset of a standard" called a
> "profile", although I think that term is kind of confusing.  I'm okay
> with saying a dialect could, in theory, be formed as a restriction on
> some other dialect, even RIF Core.

Well, I wasn't thinking that you'd *only* restrict.

> The problem is that we don't get to define a lot of these dialects
> without confusing the market.

Why is that a problem?

>   We've agreed to define one in Phase 1 and
> "a handful" in Phase 2.  This decision was based (I think) on a  
> sense of
> how much complexity the market can handle.  I can imagine ten years  
> from
> now getting up to more than a dozen dialects, if things are going very
> very well for RIF.  I think more than two a year would be a mistake.
>
> So the debate at hand is about the dialect we pick for Phrase 1 (aka,
> the RIF Core dialect, aka RIF Core).

Sure.

> We did agree in Montenegro and publish in July that "RIF must not
> require rule systems to be changed; it must be implementable via
> translators." [1] That seems to imply we need to stick with
> non-recursive Horn.

Well, if that said "RIF Core" then yes. But obviously, since dialects  
will differ, this requirement has to be interpreted carefully.

> I guess you're saying this: RIF Core might be recursive Horn, and then
> in phase 2 we could have a dialect ("RIF Business Core" heh) which is
> non-recursive Horn.

Perhaps. I was just imagining that dialects would add this  
restriction. It's a naming/branding problem of course, and you don't  
want to "use up" the good names/name attention.

> Many rule vendors would just have to wait until
> then before they could claim compliance.

This may be a problem. I don't know. How useful is recursion free  
pure horn rules for interchange? I mean, does that cover 90% of all  
the rule bases (I doubt that)? 90% of any randomly selected rulebase  
(more plausible)? What's useful (50% of 50% of rulebases)?

>   Hmmmm.   I guess it could
> work, but I still lean against it, because I think the market's  
> need for
> rules is mostly for simple rules, not for logic programming.

I don't have a ferret in this hunt, but I thought the argument from  
Michael and Frank was that there was no either natural or non-empty  
common intersection of the rules languages. Thus, a restriction  
mechanism might be needed anyway. Of course, perhaps for current  
members there is a good and useful common, nonempty intersection (I  
take this to be what Gary and others claim).

I've always been fond of the KIF conformance section:
	<http://logic.stanford.edu/kif/dpans.html#Conformance>

Perhaps having conformance dimensions as well as profiles (profiles  
correspond roughly to RIF dialects I believe) would help?

Cheers,
Bijan.

Received on Monday, 18 December 2006 08:15:44 UTC