On the Reachability Problem for Dynamic Networks of Concurrent Pushdown Systems -- Formalisms for Specifying Markovian Population Models -- Reachability for Continuous and Hybrid Systems -- Algorithmic Information Theory and Foundations of Probability -- Model Checking as A Reachability Problem -- Automatic Verification of Directory-Based Consistency Protocols -- On Yen's Path Logic for Petri Nets -- Probabilistic Model Checking of Biological Systems with Uncertain Kinetic Rates -- How to Tackle Integer Weighted Automata Positivity -- A Reduction Theorem for the Verification of Round-Based Distributed Algorithms -- Computable CTL * for Discrete-Time and Continuous-Space Dynamic Systems -- An Undecidable Permutation of the Natural Numbers -- Forward Analysis of Dynamic Network of Pushdown Systems Is Easier without Order -- Counting Multiplicity over Infinite Alphabets -- The Periodic Domino Problem Is Undecidable in the Hyperbolic Plane -- Games with Opacity Condition -- Abstract Counterexamples for Non-disjunctive Abstractions -- Cross-Checking - Enhanced Over-Approximation of the Reachable Global State Space of Component-Based Systems -- Games on Higher Order Multi-stack Pushdown Systems -- Limit Set Reachability in Asynchronous Graph Dynamical Systems.

This book constitutes the research papers presented at the 3rd International Workshop, RP 2009 held in Palaiseau, France, September 23-25, 2009. The 20 full papers of this workshop reflect reachability problems that appear in algebraic structures, computational models, hybrid systems and verification. Reachability is a fundamental problem in the context of many models and abstractions which are describing various computational processes. Topics of interest include reachability problems in infinite state systems, rewriting systems, dynamical and hybrid systems, reachability problems in logic and verification, reachability analysis in different computational models, counter, timed, cellular, communicating automata, Petri-Nets, computational aspects of algebraic structures and predictability in iterative maps and new computational paradigms. .