Reachability problem in non-uniform cellular automata

This paper deals with the CREP (Configuration REachability Problem) for non-uniform cellular automata (CAs). The cells of CAs, we have considered here, can use different Wolfram’s rules to generate their next states. We report an algorithm which decides whether or not a configuration given (non-uniform) automaton is reachable from another configuration. develop characterization tool, named Reachability tree, used theories and decision CREP. Though worst case complexity exponential in time space, but average performance very good.