Epistemic Logic and Logical Omniscience - II: A unifying framework

In a published paper entitled Epistemic Logic and Logical Omniscience: A Su rvey (Int J Intell Syst 1997, 12, 57-81) a collection of epistemic logics w ere reviewed and critiqued. This sequel paper provides evidence for the cla im that a unifying framework for various existing epistemic logics can be d efined. Of particular interest is the logic of implicit and explicit belief , the logic of awareness, and the Cadoli-Schaerf epistemic model. Although these logics appear to have surface dissimilarities, a closer examination s hows that they have a strong resemblance. The contribution of this paper is to show that a unifying framework MEL (multi-valued epistemic logic) that integrates the features of these three logics can be defined. In this paper , it is proven that the semantics of MEL subsumes the semantics of the logi c of implicit and explicit belief, the logic of awareness, and the Cadoli-S chaerf epistemic model. By placing some constraints on MEL, various epistem ic notions such as implicit belief, explicit belief, and awareness can be m odeled. (C) 2000 John Wiley & Sons, Inc.