This book constitutes the refereed proceedings of the 21st International Conference on Principles and Practice of Multi-Agent Systems, PRIMA 2018, held in Tokyo, Japan, in October/November 2018. The 27 full papers presented and 31 short papers were carefully reviewed and selected from 103 submissions. PRIMA presents subjects in many application domains, particularly in e-commerce, and also in planning, logistics, manufacturing, robotics, decision support, transportation, entertainment, emergency relief and disaster management, and data mining and analytics.

This book constitutes the revised and selected papers from the 5th International Workshop on Engineering Multi-Agent Systems held in Sao Paulo, Brazil, in May 2018, in conjunction with AAMAS 2018. The 11 full papers presented in this volume were carefully reviewed and selected from 18 submissions. The book contains also the best paper of the workshop that has been published previously in another LNCS volume. The EMAS workshop focusses on the cross-fertilisation of ideas and experiences in the various fields with the aim to enhance knowledge and expertise in MAS engineering , to improve the state-of-the-art, to define new directions for MAS engineering, to investigate how established methodologies for engineering and large-scale and open MAS can be adapted.

This volume contains the refereed proceedings of the 12th International Conference on Logic Programming and Nonmonotonic Reasoning, LPNMR 2013, held in September 2013 in Corunna, Spain. The 34 revised full papers (22 technical papers, 9 application description, and 3 system descriptions) and 19 short papers (11 technical papers, 3 application descriptions, and 5 system descriptions) presented together with 2 invited talks, were carefully reviewed and selected from 91 submissions. Being a forum for exchanging ideas on declarative logic programming, nonmonotonic reasoning, and knowledge representation, the conference aims to facilitate interactions between those researchers and practitioners interested in the design and implementation of logic-based programming languages and database systems, and those who work in the area of knowledge representation and nonmonotonic reasoning.

This Festschrift volume, published in honor of Michael Gelfond on the occasion of his 65th birthday, contains a collection of papers written by his closest friends and colleagues. Several of these papers were presented during the Symposium on Constructive Mathematics in Computer Science, held in Lexington, KY, USA on October 25-26, 2010.

The 27 scientific papers included in the book focus on answer set programming. The papers are organized in sections named Foundations: ASP and Theories of LP, KR, and NMR, ASP and Dynamic Domains, and ASP Applications and Tools ."

This book constitutes the thoroughly refereed post-workshop proceedings of the 5th International Workshop on Declarative Agent Languages and Technologies, DALT 2007, held in Honolulu, HI, USA, in May 2007 as an associated event of AAMAS 2007, the main international conference on autonomous agents and multi-agent systems.

The 11 revised full papers presented together with 1 keynote lecture and 2 invited papers from the AAMAS main conference - substantially enhanced after the workshop - were carefully selected for inclusion in the book. The papers combine declarative and formal approaches with engineering and technology aspects of agents and multiagent systems and focus especially on modeling, goals, foundational concepts, and communication.

This book constitutes the refereed proceedings of the 19th International Conference on Principles and Practice of Multi-Agent Systems, PRIMA 2016, held in Phuket, Thailand, in August 22-26, 2016. The 16 revised full papers presented together with two invited papers, 9 short papers and three extended abstracts were carefully reviewed and selected from 50 submissions. The intention of the papers is to showcase research in several domains, ranging from foundations of agent theory and engineering aspects of agent systems, to emerging interdisciplinary areas of agent-based research.

This book constitutes the refereed proceedings of the 17th International Symposium on Practical Aspects of Declarative Languages, PADL 2015, held in Portland, OR, USA, in June 2015. The 10 revised papers presented were carefully reviewed and selected from numerous submissions. The papers cover all forms of declarative concepts, including, functional, logic, constraints, etc.

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.

The workshopon Declarative Agent Languagesand Technologies(DALT), in its sixth edition this year, is a well-established forum for researchers interested in sharing their experiences in combining declarative and formal approaches with aspects of engineering and technology of agents and multiagent systems. DALT2008washeldasasatelliteworkshopofAAMAS2008, the7thInter- tional Joint Conference on Autonomous Agents and Multiagent Systems, in - toril, Portugal. Following the success of DALT 2003 in Melbourne (LNAI 2990), DALT 2004 in New York (LNAI 3476), DALT 2005 in Utrecht (LNAI 3904), DALT 2006 in Hakodate (LNAI 4327), and DALT 2007 in Honolulu (LNAI 4897), the workshop again provided a discussion forum to both (a) support the transfer of declarative paradigms and techniques to the broader community of agent researchers and practitioners, and (b) to bring the issue of designing complex agent systems to the attention of researchers working on declarative languages and technologies. TheaimoftheDALTworkshopistostimulateresearchonformalanddecl- ative approaches both for developing the foundations of multiagent systems as well as for all phases of engineering multiagent systems, i.e., for speci?cation and modeling, for implementation, and for veri?cation. By providing a forum for the presentation of ideas addressing both of these aspects, DALT encourages the integrationof formal and declarativetechniques and methods that arebased on solid theoretical foundations in the engineering of multiagent systems