- From: Axel Polleres <axel.polleres@deri.org>
- Date: Tue, 04 Dec 2007 16:14:04 +0000
- To: Pathak.Jyotishman@mayo.edu
- CC: public-rif-comments@w3.org, "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
Dear Jyoti, Sorry for the late reply, first of all.... > Hello everyone, > > I am a newcomer to this field and trying to learn. The question I > have is w.r.t. support for negation (specifically NAF: negation as > failure) and disjunction in RIF. As far as I know, SWRL natively does > not support them. Is this true for RIF as well? > > Thank you, - Jyoti Indeed, RIF's Basic Logic dialect (BLD) [1] does not support negation as failure (NAF). Extensions of rule lanaugages by NAF and other variations of negation (see [2]) are beyond phase 1 of RIF. The working group however does at this point not preclude that we will already be starting to work on dialects which include such extensions in parallel with finishing Phase 1. For instance, in the current proposal for a production rule dialect (PRD), see [3], you will find a construct for negation as failure, which is currently under discussion, i.e. this draft is not to be considered as finalized. Similar considerations apply for disjunction. Note that BLD allows disjunction in rule bodies, but not in rule heads. Again, later dialects and the generic extensibility mechanism we are currently working on shall allow for such extensions. As for SWRL, note that SWRL is an *extension* of OWL, thus, before addressing SWRL completely, we need to address OWL compatibility [4] in more detail, which is also work in progress at the moment. with best regards, Axel 1. http://www.w3.org/TR/2007/WD-rif-bld-20071030 2. http://www.w3.org/2005/rules/wg/wiki/negation 3. http://www.w3.org/2005/rules/wg/wiki/PRdialect 4. http://www.w3.org/TR/2007/WD-rif-rdf-owl-20071030/ -- Dr. Axel Polleres email: axel@polleres.net url: http://www.polleres.net/
Received on Tuesday, 4 December 2007 16:14:36 UTC