The complexity of set constraints -- On duality for the modal ?-calculus -- Short proofs of tautologies using the schema of equivalence -- Process algebra with combinators -- Is game semantics necessary? -- The model theory of concurrency -- From semantics to rules: A machine assisted analysis -- On the reasons for average superlinear speedup in parallel backtrack search -- Negation as inconsistency in PROLOG via intuitionistic logic -- Approximable minimization problems and optimal solutions on random inputs -- Bounded-arity hierarchies in fixed-point logics -- Petri nets and the equivalence problem -- Logical aspects of set constraints -- Oracles and quantifiers -- A Horn clause that implies an undecidable set of Horn clauses -- Higher-order action calculi -- A generic strong normalization argument: Application to the Calculus of Constructions -- Data types, infinity and equality in system AF 2 -- Normalization for typed lambda calculi with explicit substitution -- Program transformation and proof transformation -- Incorporating generalized quantifiers and the least fixed point operator -- "The semantics of the C programming language".