Michael Beetz and Drew McDermott, Yale University
An agent that learns about the world while performing its jobs has to plan in a exible and focused manner: it has to re ect on how to perform its jobs while accomplishing them, focus on critical aspects of important subtasks, and ignore irrelevant aspects of their context. It also has to postpone planning when lacking information, reconsider its course of action when noticing opportunities, risks, or execution failures, and integrate plan revisions smoothly into its ongoing activities. In this paper, we add constructs to rpl (Reactive Plan Language) that allow for local planning of ongoing activities. The additional constructs constitute an interface between rpl and planning processes that is identical to the interface between rpl and continuous control processes like moving or grasping. The uniformity of the two interfaces and the control structures provided by rpl enable a programmer to concisely specify a wide spectrum of interactions between planning and execution.