In the paper we introduce formal calculi which are a generalization of propositional modal logics. These calculi are called fuzzy modal logics. We introduce the concept of a fuzzy Kripke model and consider a semantics of these calculi in the class of fuzzy Kripke models. The main result of the paper is the completeness theorem of a minimal fuzzy modal logic in the class of fuzzy Kripke models. © 2005 Springer Science+Business Media, Inc.
Mironov, A. M. (2005). Fuzzy modal logics. Journal of Mathematical Sciences, 128(6), 3461–3483. https://doi.org/10.1007/s10958-005-0281-1