Modeling an agent’s incomplete knowledge during planning and execution

In many domains agents must be able to generate plans even when faced with incomplete knowledge of their environment. We provide a model to capture the evolution of the agent's knowledge as it engages in the activities of planning (where the agent must attempt to infer the e ects of hypothesized actions) and execution (where the agent must update its knowledge to re ect the actual effects of actions). The e ects (on the agent's knowledge) of a planned sequence of actions are very di erent from the e ects of an executed sequence of actions, and one of the aims of this work is to clarify this distinction. The work is also aimed at providing a model that is not only rigorous but can also be of use in developing planning systems.