Abstract
We introduce the concept of a max-min fuzzy language, FL ∨(M), and a min-max fuzzy language, FL ∧(M), recognized by a type of fuzzy automaton M. We show that if L1 and L2 are finite-valued F ∨-regular languages, then so are L1 ∪ L2 and L1 ∩ L2. We give a form of a fuzzified pumping lemma which we use to give a necessary and sufficient condition for FL ∨(M) to be nonconstant.