Abstract
Version vectors play a central role in update tracking under optimistic distributed systems, allowing the detection of obsolete or inconsistent versions of replicated data. Version vectors do not have a bounded representation; they are based on integer counters that grow indefinitely as updates occur. Existing approaches to this problem are scarce; the mechanisms proposed are either unbounded or operate only under specific settings. This paper examines version vectors as a mechanism for data causality tracking and clarifies their role with respect to vector clocks. Then, it introduces bounded stamps and proves them to be a correct alternative to integer counters in version vectors. The resulting mechanism, bounded version vectors, represents the first bounded solution to data causality tracking between replicas subject to local updates and pairwise symmetrical synchronization.

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This paper presents a survey of formal methods courses in European higher education carried out by the FME Subgroup on Education over the last two years. The survey data sample is made of 117 courses spreading over 58 higher-education institutions across 13 European countries and involving (at least) 91 academic staff. A total number of 364 websites have been browsed which are accessible from the electronic (HTML) version of the paper in the form of links to course websites, lecturers and topic entries in encyclopedias or virtual libraries. Three main projections of our sample are briefly analysed. Although far from being fully representative, these already provide some useful indicators about the impact of formal methods in European curricula on computing. © Springer-Verlag 2004.

Abstract
This paper presents a strategy for applying sampling techniques to relational databases, in the context of data quality auditing or decision support processes. Fuzzy cluster sampling is used to survey sets of records for correctness of business rules. Relational algebra estimators are presented as a data quality-auditing tool.

Abstract
Functional transposition is a technique for converting relations into functions aimed at developing the relational algebra via the algebra of functions. This paper attempts to develop a basis for generic transposition. Two instances of this construction are considered, one applicable to any relation and the other applicable to simple relations only. Our illustration of the usefulness of the generic transpose takes advantage of the free theorem of a polymorphic function. We show how to derive laws of relational combinators as free theorems of their transposes. Finally, we relate the topic of functional transposition with the hashing technique for efficient data representation.