We show that the type of reasoning performed by Forbus' 1985] Qualitative Process (QP) program can be justiied in a rst-order theory that models time and other measure spaces as real-valued quantities. We consider the QP analysis of a can of water with a safety valve being heated over a ame. We exhibit a rst-order theory for the microworld involved in this example, and we prove the correctness ...

A theory of shape is important for AI both for recognition and description of objects and for reasoning about the possible behaviours of objects. Theories of shape may be loosely classified as either volume-based or outline-based. We present a theory of the latter type, initially confined to two-dimensional outlines. We represent outlines by means of strings over an alphabet of seven qualitativ...

Objects move, collide, flow, bend, heat up, cool down, stretch, compress . and boil . These and other things that cause changes in objects over time are intuitively characterized as processes . To understand commonsense physical reasoning and make programs that interact with the physical world as well as people do we must understand qualitative reasoning about processes, when they will occur, t...