Abstract

Defeasible logic is a system of reasoning in which rules have exceptions, and when rules conflict, the one that applies most specifically to the situation wins out. This paper reports a successful application of defeasible logic to the implementation of an embedded control system. The system was programmed in d-Prolog (a defeasible extension of Prolog), and the inferences were compiled into a truth table that was encoded on a low-end PIC microcontroller. 1 Advantages of defeasible logic include conciseness and correct handling of temporal succession. It is distinct from fuzzy logic and probabilistic logic, addressing a di#erent set of problems. 1 Defeasible logic Consider the following rules for controlling an air conditioner: (1) Run the air conditioner when the temperature is over 78 # . (2) Do not run the air conditioner when the AC line voltage is low, even if the temperature is above 78 # , unless it is also above 81 # . (This reduces demand when the power company is...