We present a theory of object-orientation on the basis of the re-nement calculus. This theory allows for specifying the behaviour of objects and provides a calculus for the proof of relationships between classes such as reenement. Given two similar, but not identical classes, we present an algorithm to construct a common superclass which is reened by both classes, and an algorithm to construct ...

This paper describes how object-oriented software construction principles allow to develop extensible and reusable building blocks for the development of data flow based visual languages. First we’ll present the data flow visual language ProtoHyperflow whose object-oriented realization is discussed in the second part of the paper.

Like other Atlantic languages, Wolof has a large inventory of verbal derivation suffixes, but is exceptionally well endowed for causative with no less than eight different suffixes. This article analyzes the values these suffixes and reveals firstly double gradient distinctions concerning degrees involvement causer causee. Among two show typologically rare specialization, one being specialized ...