Hierarchy of lattice-valued fuzzy automata and decidability of their languages

In this paper, the role of local finiteness of truth values domain of fuzzy automata is analyzed, in which the truth value domain of fuzzy automata is the (commutative) lattice-ordered monoid. We introduce a hierarchy of lattice-valued fuzzy finite automata and the languages which were recognized by these automata. Besides, the role of local finiteness of truth value domain of fuzzy languages to the hierarchy of fuzzy automata, the role of some special archimedean t-norms in the hierarchy of fuzzy automata and the decidability of lattice-valued languages are also discussed.