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”.

This volume contains the final versions of a collection of papers presented at the Annual Conference of the European Association for Computer Science Logic, CSL '93, held at Swansea, UK in September 1993. The 21 full papers included were selected from a total of 62 submissions and essentially contribute to the whole area of computer science logic research. They are devoted to such topics as set constraints, lambda calculi, process algebras, program semantics, intuitionistic logics, fixed-point logics, the equivalence problem, Horn clauses, quantifiers, and proof tranformations.