Proceedings Ninth International Workshop on Reduction Strategies in Rewriting and Programming

Abstract: This volume contains selected papers presented at the 9th International Workshop on Reduction Strategies in Rewriting and Programming, WRS2009, which was held in Brasilia on the 28th June 2009, associated to RTA 2009 (the 20th International Conference on Rewriting Techniques and Applications) at RDP, the Federated Conference on Rewriting, Deduction and Programming. Reduction strategies define which (sub)expression(s) should be selected for evaluation and which rule(s) should be applied. These choices affect fundamental properties of reductions, such as completeness, laziness and efficiency in general. The WRS workshops promote research and collaboration in the area of reduction strategies and their applications in specification and programming, theorem proving, software engineering, etc.