This book constitutes the refereed proceedings of the 15th International Conference on Logic Programming and Nonmonotonic Reasoning, LPNMR 2019, held in Philadelphia, PA, USA, in June 2019.The 22 full papers and 3 short papers presented in this volume were carefully reviewed and selected from a total of 39 submissions. The papers were organized in topical sections named: applications; argumentation; foundations and complexity; knowledge representation and reasoning; and systems.

This book constitutes the refereed proceedings of the 10th International Symposium on Foundations of Information and Knowledge Systems, FoIKS 2018, held in Budapest, Hungary, in May 2018.The 20 revised full papers presented together with 1 invited talk were carefully reviewed and selected from 40 submissions. The papers address various topics such as big data; database design; dynamics of information; information fusion; integrity and constraint management; intelligent agents; knowledge discovery and information retrieval; knowledge representation, reasoning and planning; logics in databases and AI; mathematical foundations; security in information and knowledge systems; semi-structured data and XML; social computing; the semantic web and knowledge management; and the world wide web.

This Festschrift is published in honor of Gerhard Brewka on the occasion of his 60th birthday and contains articles from fields reflecting the breadth of Gerd's work. The 24 scientific papers included in the book are written by close friends and colleagues and cover topics such as Actions and Agents, Nonmonotonic and Human Reasoning, Preferences and Argumentation.

This book constitutes the thoroughly refereed post-conference proceedings of the Third International Workshop on Graph Structures for Knowledge Representation and Reasoning, GKR 2013, held in Beijing, China, in August 2013, associated with IJCAI 2013, the 23rd International Joint Conference on Artificial Intelligence. The 12 revised full papers presented were carefully reviewed and selected for inclusion in the book. The papers feature current research involved in the development and application of graph-based knowledge representation formalisms and reasoning techniques. They address the following topics: representations of constraint satisfaction problems; formal concept analysis; conceptual graphs; and argumentation frameworks.

This book constitutes the proceedings of the 14th International Workshop on Computational Logic in Multi-Agent Systems, CLIMA XIV, held in Corunna, Spain, in September 2013. The 23 regular papers were carefully reviewed and selected from 44 submissions and presented with four invited talks. The purpose of the CLIMA workshops is to provide a forum for discussing techniques, based on computational logic, for representing, programming and reasoning about agents and multi-agent systems in a formal way. This edition will feature two special sessions: Argumentation Technologies and Norms and Normative Multi-Agent Systems.