PTSC: Probability, Time and Shared-variable Concurrency
Huibiao Zhu (East China Normal University), Shengchao Qin (University of Durham), Jifeng He (East China Normal University), and Jonathan P. Bowen. Innovation in Systems and Software Engineering: A NASA Journal, Springer-Verlag, 5(4):271-284, December 2009.
A preliminary version of this paper appeared in SEW-30: 30th IEEE/NASA Software Engineering Workshop.
Complex software systems typically involve features like time, concurrency and probability, where probabilistic... more
Complex software systems typically involve features like time, concurrency and probability, where probabilistic computations play an increasing role. It is challenging to formalize languages comprising all these features. In this paper, we integrate probability, time and concurrency in one single model, where the concurrency feature is modelled using shared-variable-based communication. The probability feature is represented by a probabilistic nondeterministic choice, probabilistic guarded choice and a probabilistic version of parallel composition. We formalize an operational semantics for such an integration. Based on this model we define a bisimulation relation, from which an observational equivalence between probabilistic programs is investigated and a collection of algebraic laws are explored. We also implement a prototype of the operational semantics to animate the execution of probabilistic programs.
Keywords: Probability - Time - Shared-variable concurrency - Operational semantics - Algebraic laws - Bisimulation