The coalgebraic view on classes and objects is elaborated to include inheritance. Inheritance in coalgebraic speciication (of classes) will be understood dually to parametrization in algebraic speciication. That is, inheritance involves restriction (specialization), where parametrization involves extension. And cofree constructions are \best" restrictions, like free constructions are \best" ext...

Although the functional programming language Haskell has a powerful type class system, users frequently run into situations where they would like to be able to define or adapt instances of type classes only after the remainder of a component has been produced. However, Haskell’s type class system essentially only allows late binding of type class constraints on free type variables, and not on u...

This paper describes how to use subgroups to parameterize unipotent classes in the classical algebraic group in characteristic 2. These results can be viewed as an extension of the Bala-Carter Theorem, and give a convenient way to compare unipotent classes in a group G with unipotent classes of a subgroup X where G is exceptional and X is a Levi subgroup of classical type. AMS subject: 14L35, 2...

In this paper, we prove a generalization of Reznikov's theorem on the torsion-property of the Chern-Simons classes and in particular the torsion–property of the Deligne Chern classes (in degrees > 1) of a flat vector bundle on a smooth complex projective variety. We consider the case of a smooth quasi–projective variety with an ir-reducible smooth divisor at infinity. We define the Chern-Simons...

Representing temporal data in conceptual data models and ontologies is required by various application domains. For it to be useful for modellers to represent the information precisely and reason over it, it is essential to have a language that is expressive enough to capture the required operational semantics of the time-varying information. Temporal modelling languages have little support for...

We study an extension of monadic second-order logic of order with the uncountability quantifier “there exist uncountably many sets”. We prove that, over the class of finitely branching trees, this extension is equally expressive to plain monadic second-order logic of order. Additionally we find that the continuum hypothesis holds for classes of sets definable in monadic second-order logic over ...

Tcl[1] is an interpreted high level language suitable for scripts, small scale systems, prototypes and embedding in larger applications. C++ is a powerful compiled language that provides support for object oriented programming and is suitable for building large complex systems. But what if you could move from C++ to Tcl and back again with the ease of an object reference and a dynamically bound...

We will investigate the relation of countable closed linear orderings with respect to continuous monotone embeddability and will show that there are exactly א1 many equivalence classes with respect to this embeddability relation. This is an extension of Laver’s result [Lav71], who considered (plain) embeddability, which yields coarser equivalence classes. Using this result we show that there ar...

Java’s interfaces allow the definition of class properties independently of class inheritance. Since interfaces allow multiple inheritance, their potential for reusable code is higher than those of abstract classes. We present a technique for augmenting interfaces with skeletal implementations by using Java’s inner classes. Using this technique, we propose an extension of Java for providing ske...

We present an extended ER model with entity, role, and association as the basic constructs for object-oriented modeling. The purpose of the constructs is to support object evolution and extension for long lived objects. A class hierarchy consists of a static part and a dynamic part. The static part is a classiication of entity classes, while the dynamic part is the role classes played by entiti...