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 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 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".