This book constitutes the proceedings of the Kiel Declarative Programming Days, KDPD 2013, unifying the following conferences: the 20th International Conference on Applications of Declarative Programming and Knowledge Management (INAP 2013), the 22nd International Workshop on Functional and (Constraint) Logic Programming (WFLP 2013) and the 27th Workshop on Logic Programming (WLP 2013), held in Kiel, Germany, in September 2013. The 15 papers presented were carefully and reviewed and selected for inclusion in this book. They cover the following topics: logic programming, constraint problem...