q Inference Engine designed to handle multiple modeling
languages with different semantics
q Based on Horn logic with default negation
q ASCII & RDF/DAML based syntax
q Support for RDF and DAML+OIL (Namespaces, RDF Models)
q Part of the RuleML initiative
q Implementation based on XSB downloadable from
http://triple.semanticweb.org
FORALL Mdl @daml_oil(Mdl) {
...
 FORALL C  C[daml:subClassOf->daml:Nothing] <-
   EXISTS C1, C2 (C[daml:subClassOf-> C1;daml:subClassOf->C2]
                  and C1[daml:disjointWith->C2]).
...
}