A Comparative Study of Default Reasoning and Epistemic Processes

A comparative study between the theories of default reasoning and open logic is given.Some concepts of open logic,such as new premises,rejections by facts,reconstructions ,epistemic processes,and its limit are introduced to describe th evolution of hypotheses.An improved version of the limit theorem is given and proved.A model-theoretic interpretation of the closed normal defaults is given using the above concepts and the corresponding completeness is proved.Any extension of a closed normal default theory is proved to be the linit of a δ-partial increasing epistemic process of that theory,and vice versa.It is proved that there exist two distinct extensions of a closed normal default theory iff there is an δ-non-monotonic epistemic process of that theory.The completeness of Reiter‘s proof is also given and proved,in terms of the epistemic processes.Finally,the work is compared with Gaerdenfors‘s theory of knowledge in flux.

A comparative study of default reasoning and epistemic processes

A comparative study between the theories of default reasoning and open logic is given. Some concepts of open logic, such as new premises, rejections by facts, reconstructions, epistemic processes, and its limit are introduced to describe the evolution of hypotheses. An improved version of the limit theorem is given and proved. A model-theoretic interpretation of the closed normal defaults is given using the above concepts and the corresponding completeness is proved. Any extension of a closed normal defaalt theory is proved to be the limit of a δ-partial increasing epistemic process of that theory, and vice versa. It is proved that there exist two distinct extensions of a closed normal default theory iff there is an δ-non-monotonic epistemic process of that theory. The completeness of Reiter's proof is also given and proved, in terms of the epistemic processes. Finally, the work is compared with Gärdenfors's theory of knowledge in flux.