Reachability Problems

This book constitutes the refereed proceedings of the 9th International Workshop on Reachability Problems, RP 2015, held in Warsaw, Poland, in September 2015. The 14 papers presented together with 6 extended abstracts in this volume were carefully reviewed and selected from 23 submissions. The papers cover a range of topics in the field of reachability for infinite state systems; rewriting systems; reachability analysis in counter/timed/cellular/communicating automata; Petri nets; computational aspects of semigroups, groups, and rings; reachability in dynamical and hybrid systems; frontiers between decidable and undecidable reachability problems; complexity and decidability aspects; predictability in iterative maps and new computational paradigms.