Defining composition operators for object interaction.
Steven M. Butler, Roger Duke · 1998
Operations in object-oriented systems are often a composition of other operations, defined across multiple objects. The aim of this paper is to formally develop a suite of composition operators for specifying object interaction through operation composition. Experience with using Object-Z to design a range of object-oriented systems has suggested that four composition operators, conjunction, parallel, choice and sequential composition, are necessary and, at least for commonly occurring architectures, sufficient. In this paper, an abstract model of operations in object-oriented systems is first developed and used as the basis for defining the formal semantics of these composition operators.