Abstract

Abstract
As a complex artefact, software has to meet requirements formulated and verified at different levels of abstraction. A basic distinction is drawn between behavioural (dynamic) and data (static) aspects. From an educational point of view, although disguised under a number of different designations, both issues are usually present, but kept separated, in typical Computer Science undergraduate curricula. It is often argued that they tackle orthogonal problems through essentially different methods. This paper explores an alternative path in which students progress from equational to hybrid specifications in a uniform setting, integrating paradigms, combining data and behaviour, and dealing appropriately with systems evolution and reconfiguration.

Abstract

Abstract
Stepwise refinement of algebraic specifications is a well known formal methodology for program development. However, traditional notions of refinement based on signature morphisms are often too rigid to capture a number of relevant transformations in the context,at of software design, reuse, and adaptation. This paper proposes a new approach to refinement in which signature morphisms are replaced by logical interpretations as a means to witness refinements. The approach is first presented in the context of equational logic, and later generalised to deductive systems of arbitrary dimension. This allows, for example, relining sentential into equational specifications and the latter into modal ones.

Abstract
This paper introduces an axiomatisation for equational hybrid logic based on previous axiomatizations and natural deduction systems for propositional and first-order hybrid logic. Its soundness and completeness is discussed. This work is part of a broader research project on the development a general proof calculus for hybrid logics.

Abstract
It can be argued that participating in Free/Libre Open Source Software (FLOSS) projects can have a positive effect in the contributor's learning process. The need to collaborate with other contributors and to contribute to a project can motivate and implicitly foster learning. In order to validate such statements, it is necessary to (1) study the interactions between FLOSS projects' participants, and (2) explore the didactical value of participating in FLOSS projects, designing an appropriate questionnaire asking FLOSS contributors about their experience in FLOSS projects. In this paper, we illustrate how this questionnaire was designed and disseminated. We conclude the paper with results from 27 FLOSS projects contributors, determining that, not only they contribute and collaborate to the project and its community, but also that FLOSS contributors see that this type of activity can be regarded as a complement to formal education.