A Unified Integrated Method for Evaluating Goodness of Propositions in Several Propositional Logic Systems and Its Applications

The aim of the present paper is to provide a unified integrated method for defining the concept of truth degree of propositions in diverse propositional logic systems, including but not limited to the logic systems of classic logic CL, Lukasiewicz logic, Gödel logic, product logic, and L*(or NM) logic, as well as the corresponding fuzzy logic systems. Based on the fundamental concept of truth degree of propositions, the concepts of similarity degree and pseudo-metric between propositions are also introduced under certain conditions. Finally, a kind of approximate reasoning is proposed.