[RIF] What is in the scope of RIF and what is not?

Dear RIFers,

The RIF+QL and the RDF/OWL compatibility discussions touched a number of 
points that I would like to be sure I understand and everybody 
understands and agrees on.

One of them regards the very nature of the RIF, that is, rule _interchange_.

I have read in several postings things like "the problem is if the 
head/conclusion of a rule contains this or that, because it would make 
the rule unsafe" (e.g. in one of Enrico's mail "the problem happens if 
the query contains an existential variable (e.g. a bnode), since this 
would make the rule unsafe"): I do not understand why this is a problem 
from the view point of the RIF.

Let me explain: as I understand the use of the RIF, there is a rule 
language L1 and a rule language L2; somebody writes rules in L1 for a 
specific purpose and somebody wants to be able to translate those rules 
into L2 for some specific purpose. In this basic RIF scenario, rules are 
designed/written in L1, mapped into the RIF, mapped from RIF into L2, 
and used (e.g. executed by a rule engine, but not necessarily) in L2. 
And, in this basic scenario, a rule being safe or unsafe is the problem 
of L1 and L2 and their users and how they use the rules, not the RIF.

More generally, my understanding is that the RIF has to be able to carry 
unambiguously what a rule means, but what an application does, or what 
it may or may not do with the rule, or the consequences of using that 
rule, is out of the scope of the RIF.

Of course, my understanding may be quite naive here: it would help me 
(and maybe others), if we could provide examples fitting the basic 
scenario above (L1 -> RIF -> L2 -> application) when we discuss such 
problems, difficulties and issues.

Actually, it would help making sure that a discussion is in scope if any 
point made on the mailing list what illustrated with an example in the 
above form, thus showing where, how and to what degree it is expected to 
impact the design of the RIF, as opposed to impacting the 
receiving/using application.

Christian

Received on Tuesday, 31 January 2006 17:08:07 UTC