Abstract:

The notion of  strongly nonwandering set is introduced into a compact system, by means of which a necessary condition is given for a system to be distributively chaotic and a LiYorke chaotic subshift without distributively chaotic pairs is constructed, which shows that subshift distributional chaos is not equivalent to LiYorke chaos.

Key words: strongly nonwandering set, LiYorke chaos, distributional chaos； subshift