The proceedings of the last four meetings appeared in the Springer-Verlag LNCS series, and a selected series of papers of the English and the Portuguese meeting appeared as special issues in the Journal of Applied Non-Classical Logics and in the Journal of Automated Reasoning, respectively.

Logic Programming.- The Well-Founded Semantics Is the Principle of Inductive Definition.- Combining Introspection and Communication with Rationality and Reactivity in Agents.- Disjunctive Logic Program = Horn Program + Control Program.- Semantics of Partial-Order Programs.- Epistemic Logics.- Persistence and Minimality in Epistemic Logic.- Prohairetic Deontic Logic (PDL).- Phased Labeled Logics of Conditional Goals.- Theorem Proving.- Analysis of Distributed-Search Contraction-Based Strategies.- A Deduction Method Complete for Refutation and Finite Satisfiability.- Requirement-Based Cooperative Theorem Proving.- ?-Resolution: An Inference Rule for Regular Multiple-Valued Logics.- A Matrix Characterization for .- A Resolution Calculus for Dynamic Semantics.- Algorithms on Atomic Representations of Herbrand Models.- Non-monotonic Reasoning.- On the Intertranslatability of Autoepistemic, Default and Priority Logics, and Parallel Circumscription.- An Approach to Query-Answering in Reiter’s Default Logic and the Underlying Existence of Extensions Problem.- Towards State Update Axioms: Reifying Successor State Axioms.- Non-standard Logics.- A Mechanised Proof System for Relation Algebra Using Display Logic.- Relative Similarity Logics are Decidable: Reduction to FO2 with Equality.- A Conditional Logic for Belief Revision.- Implicates and Reduction Techniques for Temporal Logics.- A Logic for Anytime Deduction and Anytime Compilation.- Knowledge Representation.- On Knowledge, Strings, and Paradoxes.- Propositional Lower Bounds: Generalization and Algorithms.- Higher Order Logics.- Higher Order Generalization.- Invited Talks.- The Logical Characterization of Goal-Directed Behavior in the Presence of Exogenous Events Summary.- Towards Inference and Computation Mobility:The Jinni Experiment.