G. Oliva, "Stability and Level-wise Representation of Discrete-time Fuzzy Systems," International Journal of Fuzzy Systems, vol. 14, n. 2, pag. 185-192, 2012.
In this paper a framework for the representation and stability analysis of discrete-time systems with fuzzy state is provided, inspecting some conditions where the dynamic of the system is not required to be positive. Specifically, the paper addresses the stability analysis of such systems, as well as the representation of the α-level sets and the relation between stability of the fuzzy system and stability of the α-level sets.