Design for AKL with intelligent pruning -- Contradiction: When avoidance equals removal Part I -- Birkhoff's HSP-theorem for cumulative logic programs -- Finite domains and exclusions as first-class citizens -- Some experimental results in implementing a logic language with multi-head clauses on a Transputer architecture -- A language with finite sets embedded in the CLP-scheme -- Finitary partial inductive definitions as a general logic -- Programming methodologies in GCLA -- Computing cost estimates for proof strategies -- Logic programming with multiple context management schemes -- Non-procedural logic programming -- Axioms in definitional calculi -- A proposal for modules in ?Prolog -- Regular search spaces as a foundation of logic programming -- Answer sets and nonmonotonic S4 -- Contradiction: When avoidance equals removal Part II -- Cut formulae and logic programming -- Higher-order aspects of logic programming -- Representation and inference with consistent temporal propositions -- Definitional reflection and the completion -- Linear logic semantics for Concurrent Prolog.

The papers in this volume are extended versions of presentations at the fourth International Workshop on Extensions of Logic Programming, held at the University of St Andrews, March/April 1993. Among the topics covered in the volume are: defintional reflection and completion, modules in lambda-Prolog, representation of logics as partial inductive definitions, non-procedural logic programming, knowledge representation, contradiction avoidance, disjunctive databases, strong negation, linear logic programming, proof theory and regular search spaces, finite sets and constraint logic programming, search-space pruning and universal algebra, and implementation on transputer networks.