Complexity of Many-Valued Logics

Book chapter, 2002

As is the case for other logics, a number of complexity-related questions can be posed in the context of many-valued logic. Some of these, such as the complexity of the sets of satisfiable and valid formulas in various logics, are completely standard; others only make sense in a many-valued context. In this overview I concentrate on two kinds of complexity problems related to many-valued logic: first, I discuss the complexity of the membership problem in various languages, such as the satisfiable, respectively, the valid formulas in some well-known logics. Second, I discuss the size of representations of many-valued connectives and quantifiers, because this has a direct impact on the complexity of many kinds of deduction systems. I include results on both propositional and on first-order logic.