Proceedings of the Logic Colloquium. Held in Aachen, July 18-23, 1983

Contiguous R.E. Degrees.- Abstract construction of counterexamples in recursive graph theory.- Minimal degrees and 1-generic sets below 0?.- Undecidability and recursive equivalence II.- Logical syntax and computational complexity.- Subrecursive hierarchies via direct limits.- A star-finite relational semantics for parallel programs.- Between constructive and classical mathematics.- Partial closures and semantics of while: Towards an iteration-based theory of data types.- Toward logic tailored for computational complexity.- On a new notion of partial conservativity.- Finitely approximable sets.- A unified approach to constructive and recursive analysis.- On faithful interpretability.- Abstract recursion as a foundation for the theory of algorithms.- Some logical problems connected with a modular decomposition theory of automata.- Diophantine equations in a fragment of number theory.- Generalized rules for quantifiers and the completeness of the intuitionistic operators &, ?, ?, ?, ?, ?.- On subsets of the Skolem class of exponential polynomials.- Effective operators in a topological setting.- An axiomatization of the apartness fragment of the theory DLO+ of dense linear order.