Stable Model Semantics for Guarded Existential Rules and Description Logics

Abstract

We tackle a long-standing open research problem and prove the decidability of query answering under the stable model semantics for guarded existential rules, where rule bodies may contain negated atoms, and provide complexity results. The results extend to guarded Datalog+⁄− with negation, and thus provide a natural and decidable stable model semantics to description logics such as ELHI and DL-Lite_R.