Report Number: CS-TR-91-1391
Institution: Stanford University, Department of Computer Science
Title: A logic for perception and belief
Author: Shoham, Yoav
Author: del Val, Alvaro
Date: September 1991
Abstract: We present a modal logic for reasoning about perception and belief, captured respectively by the operators P and B. The B operator is the standard belief operator used in recent years, and the P operator is similarly defined. The contribution of the paper is twofold. First, in terms of P we provide a definition of perceptual indistinguishability, such as arises out of limited visual acuity. The definition is concise, intuitive (we find), and avoids traditional paradoxes. Second, we explore the bimodal B--P system. We argue that the relationship between the two modalities varies among settings: The agent may or may not have confidence in its perception, may or may not be accurate in it, and so on. We therefore define a number of agent types corresponding to these various assumptions, and for each such agent type we provide a sound and complete axiomatization of the B--P system.