Re: How core is Core?

Dave Reynolds wrote:

> [...]
> 
> (2) We take general function symbols out of Core, dropping back to
> function-free horn plus builtin predicates. Perhaps phase 1 should then
> be Core plus a first extension which puts the function symbols back in.
> That would be a test of the extensibility mechanism and allow us to both 
> have a really core Core and yet continue to deliver a 
> Horn-with-function-symbols dialect in phase 1.

I hate to say "I told you so!" but this was essentially the argument that
I developed in http://www.w3.org/2005/rules/wg/wiki/B.1.1_CLP_Formulation
when I proposed RIF Core be based on CLP rather than LP in order to free
rule systems from implementing term unification if they so desired! This
seems to have flown over the head of most apparently... :-( So Thank you
Dave for saying the same thing - albeit apparently unaware that this was
exactly my point?

To quote something I already wrote [1]:

  What I wrote about is simple: because CLP makes rules and constraints
  orthogonal, it offers a way to use rules over arbitrary data models
  - not just data and FOTs. I then focused on the OSF and DL formalisms
  seen as constraint systems for objects and inheritance. The nature of
  the rules is *not* important and may be of all kinds including Horn,
  (with or without negations or all kinds), Production, YouNameIt, ...
 

> (3) We define the notion of a dialect profile. This has been mentioned 
> before but it seems to me worth raising now because it affects the 
> extensibility discussion.
> 
> In this case I'm thinking of a profile as being a purely syntactic 
> restriction on a dialect. The ruleset metadata should be able to carry 
> the intended-profile information. I think we should define at least one 
> profile which is more PR compatible. Leaving restrictions completely 
> open doesn't do much for interop either so predefining one (or more) 
> whilst not precluding others seems like the right balance.

Music to my ears ... Abstracting data models from rules is the KEY!

> Comments?
> Dave

> The fact that none of the PR folks seem concerned with the current Core
> design is a source of surprise to me and suggests I might be getting my
> facts wrong.

Humph!?!? 
Haven't you read and heard me from the past 16 or so months? Haven't I been
loud and persistent enough??? :-(

-hak

[1] http://lists.w3.org/Archives/Public/public-rif-wg/2007Jan/0090.html

-- 
Hassan Aït-Kaci  *  ILOG, Inc. - Product Division R&D
http://koala.ilog.fr/wiki/bin/view/Main/HassanAitKaci