Expressiveness of Timed Events and Timed Languages

Timed process algebras are useful tools for the specification and verification of real-time systems. We study the expressiveness of (classes of) these algebras which deal with temporal aspects of concurrent systems by following very different interpretations: durational actions versus durationless actions, absolute time versus relative time, timed functional behavior versus time and functional behavior, local clocks versus global clocks, eagerness versus laziness versus maximal progress. The aim of this study is manifold. It permits to gain confidence on how time and time passing are modelled in the different approaches to timed process algebras. It shows that some different design decisions are not irreconcilable by presenting simple semantic-preserving mappings from an algebra to another so that techniques and analytic concepts can be transferred from one theory to the other. It allows a better understanding of the technical details and of the definitions in the different approaches in order to speculatively detect advantages/disadvantages of the used methodologies.