Towards Scalable Partial Evaluation of Declarative Programs -- Deciding Full Branching Time Logic by Program Transformation -- A Transformational Approach for Proving Properties of the CHR Constraint Store -- The Dependency Triple Framework for Termination of Logic Programs -- Goal-Directed and Relative Dependency Pairs for Proving the Termination of Narrowing -- LP with Flexible Grouping and Aggregates Using Modes -- On Inductive and Coinductive Proofs via Unfold/Fold Transformations -- Coinductive Logic Programming with Negation -- Refining Exceptions in Four-Valued Logic -- Towards a Framework for Constraint-Based Test Case Generation -- Using Rewrite Strategies for Testing BUpL Agents -- Towards Just-In-Time Partial Evaluation of Prolog -- Program Parallelization Using Synchronized Pipelining -- Defining Datalog in Rewriting Logic.

This volume constitutes the thoroughly refereed post-conference proceedings of the 19th International Symposium on Logic-Based Program Synthesis and Transformation, LOPSTR 2009, held in Coimbra, Portugal, during September 9-11, 2009. The 14 revised full papers presented together with one invited talk were carefully reviewed and selected for inclusion in the book. LOPSTR traditionally solicits papers in the areas of specification, synthesis, verification, transformation, analysis, optimization, composition, security, reuse, applications and tools, component-based software development, software architectures, agent-based software development, and program refinement.