The Frame Problem and Knowledge-Producing Actions

Richard B. Scherl, Hector J. Levesque

This paper proposes a solution to the frame problem for knowledge-producing actions. An example of a knowledge-producing action is a sense operation performed by a robot to determine whether or not there is an object of a particular shape within its grasp. The work is an extension of Reiter’s solution to the frame problem for ordinary actions and Moore' s work on knowledge and action. The properties of our specification are that knowledge-producing actions do not affect fluents other than the knowledge fluent, and actions that are not knowledge-producing only affect the knowledge fluent as appropriate. In addition, memory emerges as a side-effect: if something is known in a certain situation, it remains known at successor situations, unless something relevant has changed. Also, it will be shown that a form of regression examined by Reiter for reducing reasoning about future situations to reasoning about the initial situation now also applies to knowledge-producing actions.
