Non-monotonic Temporal Reasoning
Erik J. Sandewall, Yoav Shoham · 1995
Abstract Temporal reasoning is not restricted to reasoning about time itself; it also includes reasoning about phenomena that take place in time, i.e. reasoning about actions and change. Such reasoning is required for a number of purposes in Al programs, in particular for prediction, planning and plan modification, plan recognition, and diagnosis. These types of reasoning tasks depend crucially on the use of action laws, i.e. axioms which specify what effects an action will have or may have in a particular situation. Besides the action laws, each reasoning task typically involves (1) designation of certain actions which have been (will be, may be) performed, as well as their order of execution; (2) statements about the state of the world before the actions; (3) statements about the state of the world after the actions. In a planning task (2) and (3) are given and (1) is sought; in a prediction task (1) and (2) are given and (3) is sought, and so on.