The papers are organized in topical sections on multi-agent systems; logic programming and nonmonotonic reasoning; reasoning under uncertainty; logic programming; actions and cansation; complexity; description logics; belief revision; modal, spatial, and temporal logics; theorem proving; and applications.

Invited Talks.- Representing and Reasoning with Preferences.- Engineering of Logics for the Content-Based Representation of Information.- Formal Methods in Robotics.- Multi-agent Systems.- Games for Cognitive Agents.- Knowledge-Theoretic Properties of Strategic Voting.- The CIFF Proof Procedure for Abductive Logic Programming with Constraints.- Hierarchical Decision Making by Autonomous Agents.- Verifying Communicating Agents by Model Checking in a Temporal Action Logic.- Qualitative Action Theory.- Practical Reasoning for Uncertain Agents.- Modelling Communicating Agents in Timed Reasoning Logics.- Logic Programming and Nonmonotonic Reasoning.- On the Relation Between ID-Logic and Answer Set Programming.- An Implementation of Statistical Default Logic.- Capturing Parallel Circumscription with Disjunctive Logic Programs.- Towards a First Order Equilibrium Logic for Nonmonotonic Reasoning.- Characterizations for Relativized Notions of Equivalence in Answer Set Programming.- Equivalence of Logic Programs Under Updates.- Cardinality Constraint Programs.- Recursive Aggregates in Disjunctive Logic Programs: Semantics and Complexity.- Reasoning Under Uncertainty.- A Logic for Reasoning About Coherent Conditional Probability: A Modal Fuzzy Logic Approach.- A Logic with Conditional Probabilities.- Reasoning About Quantum Systems.- Sorted Multi-adjoint Logic Programs: Termination Results and Applications.- Logic Programming.- The Modal Logic Programming System MProlog.- Soundness and Completeness of an “Efficient” Negation for Prolog.- Logic Programs with Functions and Default Values.- Actions and Causation.- Parallel Encodings of Classical Planning as Satisfiability.- Relational Markov Games.- On the Logic of ‘Being Motivated to Achieve ?, Before ?’.- ComplexityIssues.- Representation and Complexity in Boolean Games.- Complexity in Value-Based Argument Systems.- A Polynomial Translation from the Two-Variable Guarded Fragment with Number Restrictions to the Guarded Fragment.- Description Logics.- Transforming Fuzzy Description Logics into Classical Description Logics.- Computing the Least Common Subsumer w.r.t. a Background Terminology.- Explaining Subsumption by Optimal Interpolation.- Belief Revision.- Two Approaches to Merging Knowledge Bases.- An Algebraic Approach to Belief Contraction and Nonmonotonic Entailment.- Logical Connectives for Nonmonotonicity: A Choice Function-Based Approach.- On Sceptical Versus Credulous Acceptance for Abstract Argument Systems.- Modal, Spacial, and Temporal Logics.- Line-Based Affine Reasoning in Euclidean Plane.- Measure Logics for Spatial Reasoning.- Only Knowing with Confidence Levels: Reductions and Complexity.- Time Granularities and Ultimately Periodic Automata.- Theorem Proving.- Polynomial Approximations of Full Propositional Logic via Limited Bivalence.- Some Techniques for Branch-Saturation in Free-Variable Tableaux.- Semantic Knowledge Partitioning.- Negative Hyper-resolution as Procedural Semantics of Disjunctive Logic Programs.- Applications.- Discovering Anomalies in Evidential Knowledge by Logic Programming.- Logic Programming Infrastructure for Inferences on FrameNet.- An Answer Set Programming Encoding of Prioritized Removed Sets Revision: Application to GIS.- Automatic Compilation of Protocol Insecurity Problems into Logic Programming.- Exploiting Functional Dependencies in Declarative Problem Specifications.- Combining Decision Procedures for Sorted Theories.- Meta-level Verification of the Quality of Medical Guidelines Using Interactive Theorem Proving.- Towards a Logical Analysis of Biochemical Pathways.- Systems Session.- Abductive Logic Programming with CIFF: System Description.- The DALI Logic Programming Agent-Oriented Language.- Qsmodels: ASP Planning in Interactive Gaming Environment.- A System with Template Answer Set Programs.- New DLV Features for Data Integration.- Profiling Answer Set Programming: The Visualization Component of the noMoRe System.- The PLP System.- The MyYapDB Deductive Database System.- InterProlog: Towards a Declarative Embedding of Logic Programming in Java.- IndLog — Induction in Logic.- OLEX – A Reasoning-Based Text Classifier.- Verdi: An Automated Tool for Web Sites Verification.- SATMC: A SAT-Based Model Checker for Security Protocols.- tabeql: A Tableau Based Suite for Equilibrium Logic.- tascpl: TAS Solver for Classical Propositional Logic.