Partial Evaluation of Order-sorted Equational Programs modulo Axioms -- A Formal, Resource Consumption-Preserving Translation of Actors to Haskell -- Verification of Time-Aware Business Processes using Constrained Horn Clauses -- MiniZinc with Strings -- Slicing Concurrent Constraint Programs -- A New Functional-Logic Compiler for Curry: Sprite -- lpopt: A Rule Optimization Tool for Answer Set Programming -- Symbolic Execution and Thresholding for Efficiently Tuning Fuzzy Logic Programs -- Hierarchical Shape Abstraction for Analysis of Free List Memory Allocators -- A Productivity Checker for Logic Programming -- Symbolic Abstract Contract Synthesis in a Rewriting Framework -- On the Completeness of Selective Uni_cation in Concolic Testing of Logic Programs -- CurryCheck: Checking Properties of Curry Programs -- A Hiking Trip Through the Orders of Magnitude: Deriving Efficient Generators for Closed Simply-Typed Lambda Terms and Normal Forms -- A Reversible Semantics for Erlang -- Scaling Bounded Model Checking By Transforming Programs With Arrays -- Coinductive Soundness of Corecursive Type Class Resolution -- Nominal Unification of Higher Order Expressions with Recursive Let -- Automata Theory Approach to Predicate Intuitionistic Logic.

This book constitutes the thoroughly refereed post-conference proceedings of the 26th International Symposium on Logic-Based Program Synthesis and Transformation, LOPSTR 2016, held in Edinburgh, UK, in September 2016. The 20 revised full papers presented together with the abstracts of 3 invited talks were carefully reviewed and selected from 38 submissions. The aim of the LOPSTR series is to stimulate and promote international research and collaboration on logic-based program development. LOPSTR is open to contributions in all aspects of logic-based program development, all stages of the software life cycle, and issues of both programming-in-the-small and programming-in-the-large. LOPSTR traditionally solicits contributions, in any language paradigm, in the areas of synthesis, specification, transformation, analysis and verification, specialization, testing and certification, composition, program/model manipulation, optimization, transformational techniques in SE, inversion,applications, and tools.