Abstract
Software components, arising, typically, in systems' analysis and design, are characterized by a public interface and a private encapsulated state. They persist (and evolve) in time, according to some behavioural patterns. This paper is an exercise in modeling such components as coalgebras for some kinds of endo-functors on Set, capturing both (interface) types and behavioural aspects. The construction of component categories, cofibred over the interface space, emerges by generalizing the usual notion of a coalgebra morphism. A collection of composition operators as well as a generic notion of bisimilarity, are discussed.

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Abstract
Report on the poster exhibition that took place at ECOOP'99.

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Abstract
This paper presents a technique to construct compilers expressed in a strict, purely functional setting. The compilers do not rely on any explicit data structures, like trees, stacks or queues, to efficiently perform the compilation task. They are constructed as a set of functions which are directly called by the parser. An abstract syntax tree is neither constructed nor traversed. Such deforestated compilers are automatically derived from an attribute grammar specification. Furthermore this technique can be used to efficiently implement any multiple traversal algorithm.

Abstract
Formal reasoning about how users and systems interact poses a difficult challenge. Interactive systems design provides a context in which the subjective area of human understanding meets the objectivity of computer systems logic. We present results of a case study in the use of automated reasoning to aid the formal analysis of interactive systems. We show how we can use human-factors issues to generate properties of interest, and how we can use model checking and theorem proving to analyse our specifications against those properties. This is part of ongoing work in the development of a tool to allow the automatic translation of interactor based specifications into SMV, and in the analysis of the role which different verification techniques might have during the development of interactive systems.