A Comparison of the Commonsense and Fixed Point Theories of Nonmonotonicity

Proceedings of the AAAI Conference on Artificial Intelligence, 5

Volume

Science

Knowledge Representation

The mathematical fixed point theories of nonmonotonic reasoning are examined and compared to a commonsense theory of nonmonotonic reasoning which models our intuitive ability to reason about defaults. It is shown that all of the known problems of the fixed point theories are solved by the commonsense theory. The concepts of this commonsense theory do not involve mathematical fixed points, but instead are explicitly defined in a monotonic modal quantificational logic which captures the modal notion of logical truth.