An action system is a framework for describing parallel or distributed systems, for which the refinement calculus offers a formalisation of the stepwi...

Incomplete relations are relations which contain null values, whose meaning is 'value is at present unknown'. A functional dependency (FD) is weakly...

For successful information systems development, conceptual data modeling is essential. Nowadays a plethora of techniques for conceptual data modelin...

We define two measures of 'fractalness' of gray-tone images: the degree of self-similarity and the gray-tone fractal dimension as a generalization o...

We study the decidability of the model checking problem for linear and branching time logics, and two models of concurrent computation, namely Petri...