Re: [RIF] A Modest Proposal: Work Out Some Concrete Examples; Example-1: CHANGE-BABY-IF-WET rule

Dear Allen,

You wrote:

>Hi Francois, 
>
>In my opinion the RIF should definitely allow for expressing whatever
>is necessary to enable automatic translation of rules across
>rule-systems.  By "translation" I mean an interchange that preserves at
>least "operational equivalence" (which can be defined) if not logical
>equivalence.  Perhaps such translations can be done without semantic
>information in the case of rule-systems within the same family
>(meta-model), but I think it is highly unlikely that they can be done
>across rule-systems in different families.
>
>At any rate, that was the point of the "Modest Proposal."  We should
>work out some simple concrete examples to see what is involved in this
>enterprise.  Then we will be better able to assess to what degree
>expressing semantic information is required.
>  
>
I agree that RIF should have (1) a clear declarative semantics and (2) 
in addition support conveying *some* *limited* specifications of 
procedural semantics (eg backward chaining is intended because with 
forward chaining the considered rules would require to process all/too 
many nodes on the Web).

I consider not realizable to specify a RIF "that preserves operational 
equivalence" between several rule languages.

In my opinion, the choice we are facing can be expressed as "lingua 
franca" vs. "esperanto". Lingua franca is based on an abstract model 
that abstracts out many important aspects of languages thus making 
interchange between many possible at low efforts. Esperanto is a well 
designed full-fledged language that make it possible to translate from 
or to other languages while preserving "operational equivalence". The 
Esperanto approach has two drawbacks: its design is extremly expensive 
and its acceptance is extremely low, the reason being that human being - 
including computer scientists - like using special languages - including 
computer science languages - for building up, or maintain, sub-communities.

Back to RIF: I beleive RIF should give rise to express:

- logical formulas in a FOL style (preferably using a rich syntax)
- intended use of the formulas (eg deduction rule, integrity 
constraints, ontologies)
- intended negation (monotonic or non-monotonic)
- intended declarative semantics (eg Well Founded or Stable Model or FOL)
- intended truth valuations of all kinds (including discrete truth 
valuations such as eg true/false, true/unknown/false, 
known-tue/possibly-true/possibly-false/known-false as well as continous 
truth valuations such as [0..1] 0 meaining false, etc.)
- schemas (in the acception of RDFS) ie what is also called sorts in 
automated reasoning and logic (ie classes and sub-class relationships 
and the like)
- name (not procedural semantics!) of the rule engine the rules have 
been designed for.
- maybe further "properties".

Of course, RIF should make it possible that some of the above is not 
specified with a ruleset.

Regards,
-- 
Francois

Received on Wednesday, 1 February 2006 07:58:55 UTC