Elect: An Inconsistency Handling Approach for Partially Preordered Lightweight Ontologies

We focus on the problem of handling inconsistency in light-weight ontologies. We assume terminological knowledge bases (TBoxes) are specified in DL-Lite and that assertional facts (ABoxes) are partially preordered and may be inconsistent with respect to TBoxes. One of the main contributions of this paper is the provision of an efficient and safe method, called Elect, to restore consistency of the ABox with respect to the TBox. In the case where the assertional bases are flat (no priorities are associated with the ABoxes) or totally preordered, our method collapses with the well-known IAR semantics and non-defeated semantics, respectively. The semantic justification of Elect is obtained by first viewing a partially preordered ABox as a family of totally preordered ABoxes, and then applying non-defeated inference to each of the totally preordered ABoxes. We introduce the concept of elected assertions which allows us to provide an equivalent characterization of Elect without explicitly generating all totally preordered ABoxes. Finally we show that the computation of Elect is done in polynomial time.