Re: [RIF] [UCR]: What is the RIF (revisited)

Peter has been right to state the following, I think:

a. RIF should have a formal syntax.
b. RIF should have a formal semantics.

IMO, the following can be added:

1. RIF's formal semantics might, and may be should, be more abstract 
than those of existing processable rule languages. Eg making it possible 
to express "negation as failure" without choosing between Stable Model 
and Well-Founded semsntics.

2. RIF could allow for rules the processing of which goes beyond what 
currently is widespread. Eg rules with disjunctive conclusions.

3. One reason for not delivering RIF with (the specification of) a 
processor is that a same rule can be used in different manners, each 
requiring different processors. Eg a rule stating that "all members in 
the RIF WG speak English" can be used for deriving that I speak English, 
ie been used as a deduction/derivation rule, or for checking if the 
requirement is enmfoprced, ie been unsed as an integrity constraint. In 
many practical cases, it makes very much sense to import, say 
deduction/derivation rules from a context/application A, and to use them 
as integrity constrainbts in a context/application B.

My conclusion:

Let us design a RIF with a formal language, a formal semantics leaving 
room for re-interpretations 9as examplefied above under 2 and 3), and 
let us *not* define (or specify) a processor for RIF.
-- 
Francois

Received on Wednesday, 8 February 2006 11:49:50 UTC