This book is dedicated to Marek Sergot, Professor in Computational Logic at Imperial College London, on the occasion of his 60th birthday. Professor Sergot’s scientific contributions range over many different fields. He has developed a series of novel ideas and formal methods bridging areas including artificial intelligence, computational logic, philosophical logic, legal theory, artificial intelligence and law, multi-agent systems and bioinformatics. By combining his background in logic and computing with his interest in the law, deontic logic, action, and related areas, and applying to all his capacity to understand the subtleties of social interaction and normative reasoning, Professor Sergot has opened up new directions of research, and has been a reference, an inspiration, and a model for many researchers in the fields to which he has contributed. The Festschrift includes several reminiscences and introductory essays describing Professor Sergot's achievements, followed by a series of articles on logic programming, temporal reasoning and action languages, artificial intelligence and law, deontic logic and norm-governed systems, and logical approaches to policies.

This book defines a logical system called the Protocol-theoretic Logic of Epistemic Norms (PLEN), it develops PLEN into a formal framework for representing and reasoning about epistemic norms, and it shows that PLEN is theoretically interesting and useful with regard to the aims of such a framework. In order to motivate the project, the author defends an account of epistemic norms called epistemic proceduralism. The core of this view is the idea that, in virtue of their indispensable, regulative role in cognitive life, epistemic norms are closely intertwined with procedural rules that restrict epistemic actions, procedures, and processes. The resulting organizing principle of the book is that epistemic norms are protocols for epistemic planning and control. The core of the book is developing PLEN, which is essentially a novel variant of propositional dynamic logic (PDL) distinguished by more or less elaborate revisions of PDL’s syntax and semantics. The syntax encodes the procedural content of epistemic norms by means of the well-known protocol or program constructions of dynamic and epistemic logics. It then provides a novel language of operators on protocols, including a range of unique protocol equivalence relations, syntactic operations on protocols, and various procedural relations among protocols in addition to the standard dynamic (modal) operators of PDL. The semantics of the system then interprets protocol expressions and expressions embedding protocols over a class of directed multigraph-like structures rather than the standard labeled transition systems or modal frames. The intent of the system is to better represent epistemic dynamics, build a logic of protocols atop it, and then show that the resulting logic of protocols is useful as a logical framework for epistemic norms. The resulting theory of epistemic norms centers on notions of norm equivalence derived from theories of process equivalence familiar from the study of dynamic and modal logics. The canonical account of protocol equivalence in PLEN turns out to possess a number of interesting formal features, including satisfaction of important conditions on hyperintensional equivalence, a matter of recently recognized importance in the logic of norms, generally. To show that the system is interesting and useful as a framework for representing and reasoning about epistemic norms, the author applies the logical system to the analysis of epistemic deontic operators, and, partly on the basis of this, establishes representation theorems linking protocols to the action-guiding content of epistemic norms. The protocol-theoretic logic of epistemic norms is then shown to almost immediately validate the main principles of epistemic proceduralism.

This volume presents the refereed proceedings of the 11th International Conference on Deontic Logic in Computer Science, DEON 2012, held in Bergen, Norway, in July 2012. The 14 revised papers included in the volume were carefully reviewed and selected from 29 submissions. Topics covered include logical study of normative reasoning, formal analysis of normative concepts and normative systems, formal specification of aspects of norm-governed multi-agent systems and autonomous agents, normative aspects of protocols for communication, negotiation and multi-agent decision making, formal representation of legal knowledge, formal specification of normative systems for the management of bureaucratic processes in public or private administration, and applications of normative logic to the specification of database integrity constraints.

This book constitutes the proceedings of the 12th International Workshop on Computational Logic in Multi-Agent Systems, CLIMA XII, held in Barcelona, Spain, in July 2011. The 22 papers presented were carefully reviewed and selected from 43 submissions. 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 volume features five thematic special sessions: secrets and trust, knowledge and beliefs, logics for games and social choice, cooperation, logic and languages, and norms and normative multi-agent systems.

This volume contains the refereed proceedings of the 13th International Conference on Logic Programming and Nonmonotonic Reasoning, LPNMR 2015, held in September 2015 in Lexington, KY, USA. The 290long and 11 short papers presented together with 3 invited talks, the paper reporting on the Answer Set Programming competition, and four papers presented by LPNMR student attendees at the doctoral consortium were carefully reviewed and selected from 60 submissions. LPNMR is a forum for exchanging ideas on declarative logic programming, nonmonotonic reasoning, and knowledge representation. The aim of the LPNMR conferences is to facilitate interactions between researchers interested in the design and implementation of logic-based programming languages and database systems, and researchers who work in the areas of knowledge representation and nonmonotonic reasoning.

This volume contains the lecture notes of the 11th Reasoning Web Summer School 2015, held in Berlin, Germany, in July/August 2015. In 2015, the theme of the school was Web Logic Rules. This Summer School is devoted to this perspective, and provides insight into the semantic Web, linked data, ontologies, rules, and logic.

This book constitutes the refereed proceedings of the Third International Conference on Logic and Argumentation, CLAR 2020, held in Hangzhou, China, in April 2020. The 14 full and 7 short papers presented were carefully reviewed and selected from 31 submissions. The papers cover the focus of the CLAR series, including formal models of argumentation, logics for decision making and uncertainreasoning, formal models of evidence, con rmation, and justi cation, logics forgroup cognition and social network, reasoning about norms, formal representationsof natural language and legal texts, as well as applications of argumentationon climate engineering.