In the design theory for the relational data base model [6] the decomposition of a relation scheme according to some normal form has been advocated for as one means to avoid undesired redundancy and anomalies [7,8,16]. Desired characteristics of such a decomposition in the case of a relation scheme R with an associated set F of functional dependencies are the lossless-join property and the pres...

Haskell-style functional dependencies allow the programmer to influence the type inference process by automatically deriving type improvement rules from class and instance declarations. Previous work demands that the dependency must fully cover all type parameters of a type class to guarantee confluence. Confluence is an important property to ensure that type inference is well-behaved. We resto...

Functional Dependency has been extensively studied in database theory. Most recently, there have been some works investigating the implications of extending Description Logics with functional dependencies. As it turns out, more complex functional dependencies at the type-level can lead to undecidability, which thus restricts its usage in the TBox. This paper therefore focuses on enhancing its a...

Type classes in Haskell allow programmers to define functions that can be used on a set of different types, with a potentially different implementation in each case. For example, type classes are used to support equality and numeric types, and for monadic programming. A commonly requested extension to support ‘multiple parameters’ allows a more general interpretation of classes as relations on ...

Functional Dependency (FD) has been extensively studied in database theory. Most recently there have been some works investigating the implications of extending Description Logics with functional dependencies. In particular the OWL ontology language offers the functional property property allowing simple functional dependency to be specified. As it turns out, more complex FD specified as concep...

Data integrity constraints usually form a major component in a data-intensive business system. To successfully reengineer a data-intensive business system, its data integrity constraints must be understood. Functional dependencies constitute an important type of data integrity constraints. Due to the nature of system development, a significant amount of functional dependencies is usually omitte...

Classical database theory is largely a theory of relations. Relations are sets of tuples in which no duplicate tuples occur. In practice, duplicate elimination is an operation that is considered to be too expensive in many situations. Fundamental classes of integrity constraints interact differently over bags than they do over relations. This holds for keys and functional dependencies, for exam...

Functional dependencies are a popular and useful extension to Haskell style type classes. We give a reformulation of functional dependencies in terms of Constraint Handling Rules (CHRs). In previous work, CHRs have been employed for describing user-programmable type extensions in the context of Haskell style type classes. Here, we make use of CHRs to provide for the first time a concise result ...