Foundations of Information and Knowledge Systems [electronic resource] : 4th International Symposium, FoIKS 2006, Budapest, Hungary, Februrary 14-17, 2006. Proceedings / edited by Jürgen Dix, Stephen J. Hegner.

Invited Presentation -- The Semijoin Algebra -- Regular Papers -- Equational Constraint Solving Via a Restricted Form of Universal Quantification -- Modeling the Evolution of Objects in Temporal Information Systems -- Controlled Query Evaluation with Open Queries for a Decidable Relational Submodel -- Iterative Modification and Incremental Evaluation of Preference Queries -- On the Number of Independent Functional Dependencies -- Arity and Alternation: A Proper Hierarchy in Higher Order Logics -- Solving Abduction by Computing Joint Explanations: Logic Programming Formalization, Applications to P2P Data Integration, and Complexity Results -- The Nested List Normal Form for Functional and Multivalued Dependencies -- Axiomatising Functional Dependencies for XML with Frequencies -- Guarded Open Answer Set Programming with Generalized Literals -- Reasoning Support for Expressive Ontology Languages Using a Theorem Prover -- Consistency Checking Algorithms for Restricted UML Class Diagrams -- Some Contributions to the Minimum Representation Problem of Key Systems -- On Multivalued Dependencies in Fixed and Undetermined Universes -- Preference-Based Query Tuning Through Refinement/Enlargement in a Formal Context -- Processing Ranked Queries with the Minimum Space -- Hybrid Minimal Spanning Tree and Mixture of Gaussians Based Clustering Algorithm.

This volume contains the papers presented at the 4th International Symposium on Foundations of Information and Knowledge Systems (FoIKS 2006), which was held at the Alfr´ ed R´ enyi Institute of Mathematics, Hungarian Academy of Sciences, Budapest, Hungary, from February 14 to 17, 2006. FoIKS is a biennial event with a focus on the theoretical foundations of information and knowledge systems. The goal is to bring together researchers working on the theoretical foundations of information and knowledge systems, as well as to attract researchers working in mathematical ?elds such as discrete mathematics, combinatorics, logics and ?nite model theory who are interested in applying their theories to research on database and knowledge base theory. FoIKS took up the tradition of the conference series Mathematical Fun- mentals of DatabaseSystems (MFDBS), which enabled East-West collaboration in the ?eld of database theory. The ?rst FoIKS symposium was held in Burg, Spreewald (Germany) in 2000, the second FoIKS symposium was held in Salzau Castle (Germany) in 2002, and the third FoIKS symposium was held in Vienna (Austria) in 2004.Former MFDBS conferences were held in Dresden (Germany) in 1987, Visegr´ ad (Hungary) in 1989 and in Rostock (Germany) in 1991. P- ceedingsofthese previousMFDBSandFoIKSeventswerepublishedbySpringer as volumes 305, 364, 495, 1762, 2284, and 2942 of the LNCS series, respectively.