A general top-down algorithmization for the Well-Founded MKNF Semantics - a semantics for combining rules and
ontologies - was recently defined based on an extension of SLG resolution for Logic Programming with an abstract oracle to the parametric ontology language. Here we provide a concrete oracle with practical usage, namely for EL+ which is tractable for reasoning tasks like subsumption. We show that the defined oracle remains tractable
(wrt. data complexity) so that the combined (query-driven) approach of non-monotonic rules with that oracle is tractable as well.