“…However, even when the sequences of matrices are finite, the number of different elements in sequences can be high. For the reasons above, different authors have proposed an approximate approach not only in the context of state reduction but also in some other close contexts, such as containment and equivalence of fuzzy automata, as well as simulations and bisimulations between fuzzy automata (see [3,8,9,10,11,13,12,15,18,19,21] and articles cited there).…”