X id → X → 0→ · For any morphism u : X → Y , there is an object Z (called a mapping cone of the morphism u) fitting into a distinguished triangle X u − → Y → Z → · Any triangle isomorphic to a distinguished triangle is distinguished. This means that if X u − → Y v − → Z w −→ X[1] is a distinguished triangle, and f : X → X, g : Y → Y , and h : Z → Z are isomorphisms, then X′ gu f −1 −−−−→ Y ′ hv...

Software merging is needed at different stages of software development to combine the artifacts created or modified by the parallel work of the different developers involved in the project. An accurate matching approach is the key to successful software merging as well as to conflicts identification. In this paper, a new matching approach for ObjectOriented formal specifications is proposed. Ob...

Refactoring is a method for improving the structure of programs/specifications as to enhance readability, modularity and reusability. Refactorings are required to be behaviour-preserving in that – to an external observer – no difference between the program before and after refactoring is visible. In this paper, we develop refactorings for an object-oriented specification formalism combining a s...

The ‘viewpoint’ approach, in which a system is described by several partial specifications, has been proposed as a way of making complex computing systems more understandable. The ISO’s Open Distributing Processing (ODP) framework is an architecture for open distributed systems, involving five named viewpoints. This paper compares two partial specifications of a lending library — from the ODP’s...

This paper presents a framework for compositional verification of Object-Z specifications. Its key feature is a proof rule based on decomposition of hierarchical Object-Z models. For each component in the hierarchy local properties are proven in a single proof step. However, we do not consider components in isolation. Instead, components are envisaged in the context of the referencing super-com...

In this paper we discuss the relationship between notions of non-atomic (or action) refinement in a state-based setting with that in a behavioural setting. In particular, we show that the definition of non-atomic coupled downward simulation as defined for Z and Object-Z is sound with respect to an action refinement definition of CSP failures refinement.

The use of multiple partial viewpoints is recommended for specification. We believe they also can be useful for devising strategies for testing. In this paper, we use Object-Z to formally specify concurrent Java components from viewpoints based on the separation of application and synchronisation concerns inherent in Java monitors. We then use the Test-Template Framework on the Object-Z viewpoi...

In the context of large scale industrial installations, model checking often fails to tap its full potential because of a missing link between a system’s specification and its functional and non-functional requirements, like safety. Our work bridges this gap by providing a translation from the formal specification language Object-Z to the SMV model checker input language to combine their advant...

UML is a standard modelling language that is able to specify a wide range of object-oriented concepts. Among them, we have collaborations, that serve to realise use cases, a powerful abstraction concept. The behaviour part of a collaboration is rendered using collaboration diagrams. However, the lack of formalisation compromises the precision of the specification. By using formal description te...

From examination of only 4 deg of sky in the NOAO Deep Wide-Field Survey (NDWFS) region, we have identified the first radio-loud quasar at a redshift z > 6. The object, FIRST J1427385+331241, was discovered by matching the FLAMEX IR survey to FIRST survey radio sources with NDWFS counterparts. One candidate z > 6 quasar was found, and spectroscopy with the Keck II telescope confirmed its identi...