- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Wed, 04 Jul 2007 09:32:52 +0100
- To: Bijan Parsia <bparsia@cs.man.ac.uk>
- CC: public-rif-wg@w3.org
Bijan Parsia wrote: > The strongest thing I'd personally say is that there will be multiple > implementations of DL Safe SWRL rules in owl engines which will want to > exchange rulesets with each other and with other systems as appropriate. > I believe that the user base will be pretty happy with that. Seems reasonable. Would that community be happy with continuing to use DL Safe SWRL for interchange or is there some additional need that a compatible RIF dialect would satisfy? > (This, of course, says nothing specific about what "goes into" Core.) Quite so. >> This subset of Core is implementable in both production rule and LP >> settings. > [snip] > > I thought a sticking point was recursion? I don't think so, I believe the issue is the ability to build recursive data structures. Certainly is known (e.g. [1]) that for both datalog and semi-positive datalog[*] the production style fixed-point semantics and the declarative (minimal model) semantics coincide. Dave [1] http://citeseer.ist.psu.edu/vianu96rulebased.html [*] Semi-positive datalog = datalog with negation over just the edb relations (i.e. relations not mentioned in rule conclusions), which is what I meant by closed-world negation over dataset partitions. -- Hewlett-Packard Limited Registered Office: Cain Road, Bracknell, Berks RG12 1HN Registered No: 690597 England
Received on Wednesday, 4 July 2007 08:33:07 UTC