From Hilbert's Program to a Logic Toolbox -- On the Notion of Vacuous Truth -- Whatever Happened to Deductive Question Answering? -- Decidable Fragments of Many-Sorted Logic -- One-Pass Tableaux for Computation Tree Logic -- Extending a Resolution Prover for Inequalities on Elementary Functions -- Model Checking the First-Order Fragment of Higher-Order Fixpoint Logic -- Monadic Fragments of Gödel Logics: Decidability and Undecidability Results -- Least and Greatest Fixed Points in Linear Logic -- The Semantics of Consistency and Trust in Peer Data Exchange Systems -- Completeness and Decidability in Sequence Logic -- HORPO with Computability Closure: A Reconstruction -- Zenon: An Extensible Automated Theorem Prover Producing Checkable Proofs -- Matching in Hybrid Terminologies -- Verifying Cryptographic Protocols with Subterms Constraints -- Deciding Knowledge in Security Protocols for Monoidal Equational Theories -- Mechanized Verification of CPS Transformations -- Operational and Epistemic Approaches to Protocol Analysis: Bridging the Gap -- Protocol Verification Via Rigid/Flexible Resolution -- Preferential Description Logics -- On Two Extensions of Abstract Categorial Grammars -- Why Would You Trust B? -- How Many Legs Do I Have? Non-Simple Roles in Number Restrictions Revisited -- On Finite Satisfiability of the Guarded Fragment with Equivalence or Transitive Guards -- Data Complexity in the Family of Description Logics -- An Extension of the Knuth-Bendix Ordering with LPO-Like Properties -- Retractile Proof Nets of the Purely Multiplicative and Additive Fragment of Linear Logic -- Integrating Inductive Definitions in SAT -- The Separation Theorem for Differential Interaction Nets -- Complexity of Planning in Action Formalisms Based on Description Logics -- Faster Phylogenetic Inferencewith MXG -- Enriched ?-Calculus Pushdown Module Checking -- Approved Models for Normal Logic Programs -- Permutative Additives and Exponentials -- Algorithms for Propositional Model Counting -- Completeness for Flat Modal Fixpoint Logics -- : Decidable Non-monotonic Disjunctive Logic Programs with Function Symbols -- The Complexity of Temporal Logic with Until and Since over Ordinals -- ATP Cross-Verification of the Mizar MPTP Challenge Problems.