Re: [RIF] Extensible Design

From: Sandro Hawke <sandro@w3.org>
Subject: Re: [RIF] Extensible Design 
Date: Thu, 04 May 2006 14:01:02 -0400

> 
> > > What does mean "Semantics: none"?
> > 
> > Something like:
> > 
> > The RIF will have no model theory.  The RIF will have no proof theory. In
> > sum, the RIF will just be concerned with rules as data - not as syntactic
> > constructs in a logic.
> > 
> > Compliance of a tool with the RIF will be defined as
> > 1/ being able to accept (all) valid RIF documents;
> > 2/ being able to emit (a reasonable number of) valid RIF documents;
> >    and
> > 3/ accepting an emitted RIF document results in the same internal "state"
> >    that caused the emission. 
> > The last condition would be measured by identifying a number of RIF
> > documents that are faithfully processed (i.e., no information is lost) and 
> > demonstrating that the emission of a RIF document after accepting one of
> > these RIF documents into a clean system results in the document itself.
> 
> That design doesn't provide for interchange between rule systems,
> though, does it?

It does, in the sense that two RIF-compliant tools can interchange rules.
It may be that some sense of meaning is not preserved in the interchange,
of course.

> I'm starting to think that the question "does RIF have semantics" is not
> well formed.  Perhaps each particular RIF dialect will have a formal
> syntax and a formal semantics, and RIF on the whole will just be some
> XML packaging machinery (corresponding to the RIFRAF ontology).

This approach could easily lead to a different RIF dialect for each
RIF-compliant tool, which doesn't do much for interoperability.

> Hopefully there can be many modules shared between dialects, where both
> the syntax and semantics are shared.   I'm not sure if it'll ever make
> sense to share syntax but not semantics for some part of a language.

Well, it seems to me that the proposal by Boley et al advocates precisely
this view.  My reading of the proposal is that several (perhaps many) RIF
dialects will share the same syntax (or very similar syntaxes) for
conditions but will diverge on semantics.

>        -- Sandro

peter

Received on Thursday, 4 May 2006 18:22:51 UTC