Closed World Assumption for Disjunctive Reasoning

In this paper, the relationship between argumentation and closed world reasoning for disjunctive information is studied. In particular, the authors propose a simple and intuitive generalization of the closed world assumption (CWA) for general disjunctive deductive databases (with default negation). This semantics, called DCWA, allows a natural argumentation-based interpretation and can be used to represent reasoning for disjunctive information. We compare DCWA with GCWA and prove that DCWA extends Minker's GCWA to the class of disjunctive databases with default negation. Also we compare our semantics with some related approaches. In addition, the computational complexity of DCWA is investigated.