Goal change

Although there has been much discussion of belief change (e.g., [G¨ardenfors, 1988; Spohn, 1988]), goal change has not received much attention. In this paper, we propose a method for goal change in the framework of Reiter's [2001] theory of action in the situation calculus [McCarthy and Hayes, 1969; Levesque et al., 1998], and investigate its properties. We extend the framework developed by Shapiro et al. [1998] and Shapiro and Lesp´erance [2001], where goals and goal expansion were modelled, but goal contraction was not