Abstract
The paper explores the role that formal modeling may play in aiding the visualization and implementation of usability requirements of a control panel. We propose that this form of analysis should become a systematic and routine aspect of the development Of Such interfaces. We use a notation for describing the interface that is convenient to use by software engineers, and describe a set of tools designed to make the process systematic and exhaustive.

Abstract
In recent years, several approaches to the analysis of automation systems dependability through the application of formal verification techniques have been proposed. Much of the research has been concerned with the modelling languages used, and how best to express the automation systems, so that automated verification might be possible. Less attention, however, has been devoted to the process of writing properties that accurately capture the requirements that need verification. This is however a crucial aspect of the verification process. Writing appropriate properties, in a logic suitable for verification, is a skilful process, and indeed there have been reports of properties being wrongly expressed. In this paper we put forward a tool and a collection of property patterns that aim at providing help in this area. Copyright

Abstract
Analytic usability analysis methods have been proposed as an alternative to user testing in early phases of development due to the cost of the latter approach. By working with models of the systems, analytic models are not capable of identifying implementation related problems that might have an impact on usability. Model-based testing enables the testing of an implemented software artefact against a model of what it should be (the oracle). In the case of model-based user interface testing, the models should be expressed at an adequate level of abstraction, adequately modelling the interaction process. This paper describes an effort to develop tool support enabling the use of task models as oracles for model-based testing of user interfaces.

Abstract
Confined separation logic is a new extension to separation logic designed to deal with problems involving dangling references within shared mutable structures. In particular it allows for reasoning about confinement in object-oriented programs. In this paper, we discuss the semantics of such an extension by defining a relational model for the overall logic, parametric on the shapes of both the store and the heap. This model provides a simple and elegant interpretation of the new confinement connectives and helps in seeking for duals. A number of properties of this logic are proved calculationally.

Abstract
Invariants, bisimulations and assertions are the main ingredients of coalgebra theory applied to software systems. In this paper we reduce the first to a particular case of the second and show how both together pave the way to a theory of coalgebras which regards invariant predicates as types. An outcome of such a theory is a calculus of invariants' proof obligation discharge, a fragment of which is presented in the paper. The approach has two main ingredients: one is that of adopting relations as "first class citizens" in a pointfree reasoning style; the other lies on a synergy found between a relational construct, Reynolds' relation on functions involved in the abstraction theorem on parametric polymorphism and the coalgebraic account of bisimulations and invariants. This leads to an elegant proof of the equivalence between two different definitions of bisimulation found in coalgebra literature (due to B. Jacobs and Aczel & Mendler, respectively) and to their instantiation to the classical Park-Milner definition popular in process algebra.

Abstract
Galculator is the name of the prototype of a proof assistant of a special brand: it is solely based on the algebra of Galois connections. When combined with the pointfree transform and tactics such as the indirect equality principle, Galois connections offer a very powerful, generic device to tackle the complexity of proofs in program verification. The paper describes the architecture of the current Calculator prototype, which is implemented in Haskell in order to steer types as much as possible. The prospect of integrating the Galculator with other proof assistants such as e.g. Coq is also discussed. Copyright © 2008 ACM.