Dynamic Interactions between Goals and Beliefs

Shapiro et al. [2005; 2006], presented a framework for representing goal change in the situation calculus. In that framework, agents adopt a goal when requested to do so (by some agent reqr ), and they remain committed to the goal unless the request is cancelled by reqr . A common assumption in the agent theory literature, e.g., [Cohen and Levesque, 1990; Rao and Georgeff, 1991], is that achievement goals that are believed to be impossible to achieve should be dropped. In this paper, we incorporate this assumption into Shapiro et al.’s framework, however we go a step further. If an agent believes a goal is impossible to achieve, it is dropped. However, if the agent later believes that it was mistaken about the impossibility of achieving the goal, the agent might readopt the goal. In addition, we consider an agent’s goals as a whole when making them compatible with their beliefs, rather than considering them individually.