Re: [RIF] [UCR]: What is the RIF (revisited) --> disjunctive conclusions

Michael Kifer wrote:
> I believe that when people talk about disjunctive heads, they mean
> deductive rules. Integrity constraint like the above are represented as
> queries in LP and DBs. It is a query with an implication in the body, which
> has a disjunction in the head (of that embedded implication). Lloyd-Topor
> transforms it into constraints with no disjunction or implication.

+1, although definitly this needs (scoped, according to the charter) naf 
(when using lloyd-topor) if we allow it in phase 1 already, right?

> Since we already discussed that RIF rulesets could be tagged with semantics
> to let the recipient understand the intended meaning, I don't see
> significant obstacles to allowing disjunctions in the heads of deductive
> rules when these are tagged with classical or stable-model semantics. The
> recipient engine can reject such rules, if it doesn't have an engine to
> process them.

+1, rather RIF should IMHO
a) determine which combinations of semantic "features" are combinable, 
and which not, and
b) define what the allowed combinations of particular features mean 
semantically, and
c) define these features around a least-common-denominator core plus 
extensability mechanism, which is to be determined in phase 1.

  Do I correctly infer this to be the agreement?

> This mechanism doesn't seem to be too controversial to me and I don't quite
> understand what all the fight is about.

+1 again.

hope that this attempt to sum up was not merely a repitition of the 
arguments,
axel

-- 
Dr. Axel Polleres
email: axel@polleres.net  url: http://www.polleres.net/

Received on Thursday, 9 February 2006 16:10:16 UTC