Bulletin of the EATCS, Volume 44

Volume 44, June 1991

• Hartmut Ehrig, Michael Baldamus, Fernando Orejas: Amalgamation and Extension in the Framework of Specification Logics and Generalized Morphisms. 129-143
• Hans-Jörg Kreowski: Aspects of Systems of Logic Programming. 144-146

• Kenneth Kunen: Declarative Semantics of Logic Programming. 147-167

• Valtteri Niemi: Density in discrete systems. 168-177

• Bruno Courcelle: On Constructing Obstruction Sets of Words. 178-186
• Philippe Darondeau: Recursive Graphs are not Stable under Maximal Reduction. 186-189
• Oscar H. Ibarra: On Resetiting DLBA's. 190-191
• David Murphy: The Physics of Observation a Perspective for Concurrency Theorists. 192-201
• Zdzislaw Pawlak: Decision Logik. 201-225
• Arto Salomaa, Kai Salomaa, Sheng Yu: Primary Types of Instances of the Post Correspondence Problem. 226-241