In this paper, we propose an extended relational model to accommodate exclusive-or disjunctive information. The proposed model is defined by first-order logic. The answers to a query contain both sure answers and maybe answers. To guarantee that the manipulation power of the proposed model is as good as that of the classical relational model, we prove that the classical properties of the database, uniquely determined and well-defined relational algebra, are preserved in our proposed model.
Journal of Information Science and Engineering 20(5), p.981-999