Invited Lecture -- The Case of Pragma-Dialectics -- Foundations -- A Logic of Abstract Argumentation -- On the Meta-logic of Arguments -- Nested Argumentation and Its Application to Decision Making over Actions -- Testing Formal Dialectic -- Negotiation -- Formal Handling of Threats and Rewards in a Negotiation Dialogue -- Argument-Based Negotiation in a Social Context -- Practical Strategic Reasoning and Adaptation in Rational Argument-Based Negotiation -- A Protocol for Arguing About Rejections in Negotiation -- Protocols -- New Types of Inter-agent Dialogues -- Argumentation Based Modelling of Embedded Agent Dialogues -- Liberalizing Protocols for Argumentation in Multi-agent Systems -- Protocol Synthesis with Dialogue Structure Theory -- Deliberation and Coalition Formation -- An Argumentation-Based Model for Reasoning About Coalition Structures -- Argumentation-Based Multi-agent Dialogues for Deliberation -- Consensus Formation -- Presentation of Arguments and Counterarguments for Tentative Scientific Knowledge -- Towards a Formal Framework for the Search of a Consensus Between Autonomous Agents -- Argumentation-Supported Information Distribution in a Multiagent System for Knowledge Management -- How Agents Alter Their Beliefs After an Argumentation-Based Dialogue.