A process algebraic framework for specification and validation of real-time systems
Adnan Sherif, Ana Cavalcanti, He Jifeng, Augusto C. A. Sampaio · Formal Aspects of Computing · 2009
Abstract Following the trend to combine techniques to cover several facets of the development of modern systems, an integration of Z and CSP, calledCircus, has been proposed as a refinement language; its relational model, based on the unifying theories of programming (UTP), justifies refinement in the context of both Z and CSP. In this paper, we introduceCircus Time, a timed extension ofCircus, and present a new UTP time theory, which we use to give semantics toCircus Timeand to validate some of its laws. In addition, we provide a framework for validation of timed programs based on FDR, the CSP model-checker. In this technique, a syntactic transformation strategy is used to split a timed program into two parallel components: an untimed program that uses timer events, and a collection of timers. We show that, with the timer events, it is possible to reason about time properties in the untimed language, and so, using FDR. Soundness is established using a Galois connection between the untimed UTP theory ofCircus(and CSP) and our time theory.