Normal forms and truth tables for fuzzy logics

In this paper, we examine and compare De Morgan-, Kleene-, and Booleandisjunctive and conjunctive normal forms and consider their role in fuzzy settings. In particular, we describe normal forms and truth tables for classical fuzzy propositional logic and interval-valued fuzzy propositional logic that are completely analogous to those for Boolean propositional logic. Thus, determining logical equivalence of two expressions in fuzzy propositional logic is a …nite problem, and similarly for the interval-valued case. Turksen’s work on interval-valued fuzzy sets is reviewed in light of these results.