Abstract
This paper addresses objectification, a formal specification technique which inspects the potential for object-orientation of a declarative model and brings the 'implicit objects' explicit. Criteria for such objectification are formalized and implemented in a runnable prototype tool which embeds VDM-SL into VDM++. The paper also includes a quick presentation of a (coinductive) calculus of such generated objects, framed as generalised Moore machines.

Abstract
When modelling complex interactive systems, traditional interactor-based approaches suffer from lack of expressiveness regarding the composition of the different interactors present in the user interface model into a coherent system. In this paper we investigate an alternative approach to the composition of interactors for the specification of complex interactive systems which is based on the coordination paradigm. We layout the fundations for the work and present an illustrative example. Lines for future work are identified.

Abstract
Although presented with a variety of 'flavours', the notion of an interactor, as an abstract characterisation of an interactive component, is well-known in the area of formal modelling techniques for interactive systems. Tins paper replaces traditional, hierarchical, 'tree-like' composition of interactors in the specification of complex interactive systems, by their exogenous coordination through general-purpose software connectors which assure the flow of data and the meet of synchronisation constraints. The paper's technical contribution is twofold. First a modal logic is defined to express behavioural properties of both interactors and connectors. The logic is new in the sense that its modalities are indexed by fragments of sets of actions to cater for action co-occurrence. Then, tins logic is used in the specification of both interactors and coordination layers which orchestrate their interconnection.

Abstract
Although much of mathematics is algorithmic in nature, the skills needed to formulate and solve algorithmic problems do not form an integral part of mathematics education. In particular, logic, which is central to algorithm development, is rarely taught explicitly at pre-university level, under the justification that it is implicit in mathematics and therefore does not need to be taught as an independent topic. This paper argues in the opposite direction, describing a one-week workshop done at the University of Minho, in Portugal, whose goal was to introduce to high-school students calculational principles and techniques of algorithmic problem solving supported by calculational logic. The workshop resorted to recreational problems to convey the principles and to software tools, the Alloy Analyzer and Netlogo, to animate models.

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