This book constitutes the thoroughly refereed post-proceedings of the Joint ERCIM/Compulog-Net Workshop on New Trends in Constraints held in Paphos, Cyprus, Greece in October 1999. The 12 revised full research papers presented together with four surveys by leading researchers were carefully reviewed. The book is divided in topical sections on constraint propagation and manipulation, constraint programming, and rule-based constraint programming.

This book constitutes the proceedings of the 15th European Conference on Logics in Artificial Intelligence, JELIA 2016, held in Larnaca, Cyprus, in November 2015. The 32 full papers and 10 short papers included in this volume were carefully reviewed and selected from 88 submissions. The accepted papers span a number of areas within Logics in AI, including: belief revision, answer set programming, argumentation, probabilistic reasoning, handling inconsistencies, temporal logics and planning, description logics, and decidability and complexity results.