Chaos of a sequence of maps in a metric space☆

During the last two decades, chaos of a time-invariant map on a metric space has been extensively studied in the literature. In this paper, by introducing several new concepts, chaos of a time-varying map (i.e., a sequence of time-invariant maps) in a metric space is discussed and, by using these new concepts, broader chaotic discrete dynamical systems are further studied with several new results derived.