Theoretical Computer Science, Volume 78

Volume 78, Number 1, 21 January 1991

Georges Gardarin: Selected Papers of the Workshop on Deductive Database Theory, Illiers-Combray, France, 1989, Forword. 1
Nicole Bidoit: Negation in Rule-Based Database Languages: A Survey. 3-83
Nicole Bidoit, Christine Froidevaux: Negation by Default and Unstratifiable Logic Programs. 86-112
Véronique Royer: The Semantics of Incomplete Databases as an Expression of Preferences. 113-136
Serge Abiteboul, Eric Simon: Fundamental Properties of Deterministic and Nondeterministic Extensions of Datalog. 137-158
Serge Abiteboul, Paris C. Kanellakis, Gösta Grahne: On the Representation and Querying of Sets of Possible Worlds. 158-187
Jean-Paul Delahaye, V. Thibau: Programming in Three-valued Logic. 189-216
Bruno Courcelle: Recursive Queries and Context-free Graph Grammars. 217-244
Robert Demolombe: An Efficient Strategy for Non-Horn Deductive Databases. 245-259

Joost Engelfriet, Heiko Vogler: Modular Tree Transducers. 267-303
Rodney G. Downey: On Computational Complexity and Honest Polynomial Degrees. 305-317
R. König: Graphs and Free Partially Commutative Monoids. 319-346
Tero Harju, Juhani Karhumäki: The Equivalence Problem of Multitape Finite Automata. 347-355
David A. Mix Barrington, James C. Corbett: A Note on Some Languages in Uniform ACC0. 357-362
Ricardo A. Baeza-Yates: Searching Subsequences. 363-376
G. Burosch, János Demetrovics, Gyula O. H. Katona, Daniel J. Kleitman, Alexander A. Sapozhenko: On the Number of Databases and Closure Operations. 377-381