An Unbounded Nondeterministic Model for CSP-like Languages

The main contribution of this paper is the introduction of unbounded nondeterminism into CSP-like languages with specification, which increases the expressive power of the specification language. This is achieved by extending the finite message set of such mixed languages to an infinite one. A denotational semantics and a refinement order are defined for such a language and the CSP constructors are proved to be monotone on the specification space and continuous on the process space, which are needed for a simple treatment of iterations on both spaces of the mixed CSP-like language.