Two process–algebraic approaches have been developed for comparing two bisimulation–equivalent processes with respect to speed: the one of Moller/Tofts equips actions with lower time bounds, while the other by Lüttgen/Vogler considers upper time bounds instead. This paper sheds new light onto both approaches by testifying to their close relationship and brings the research into bisimulation–bas...

We consider a risk preference given by a total preorder < on the setM1,c of probability distributions on R with compact support, that is, a transitive binary relation such that for all μ, ν ∈ M1,c one has μ < ν or μ 4 ν or both. Elements μ ofM1,c are understood as lotteries, and μ < ν means that μ is at least as risky as ν. The goal of the paper is to provide conditions under which < has a nume...

We propose a process calculus to model high level wireless systems, where the topology of a network is described by a digraph. The calculus enjoys features which are proper of wireless networks, namely broadcast communication and probabilistic behaviour. We first focus on the problem of composing wireless networks, then we present a compositional theory based on a probabilistic generalisation o...

The client must preorder relates tests (clients) instead of processes (servers). The existing characterisation of this preorder is unsatisfactory for it relies on the notion of usable clients which, in turn, are defined using an existential quantification over the servers that ensure client satisfaction. In this paper we characterise the set of usable clients for finite-branching LTSs, and give...

This paper studies the relationships between three notions of behavioural preorder that have been proposed in the literature: refinement over modal transition systems, and the covariant-contravariant simulation and the partial bisimulation preorders over labelled transition systems. It is shown that there are mutual translations between modal transition systems and labelled transition systems t...

This paper studies the relationships between three notions of behavioural preorder that have been proposed in the literature: refinement over modal transition systems, and the covariant-contravariant simulation and the partial bisimulation preorders over labelled transition systems. It is shown that there are mutual translations between modal transition systems and labelled transition systems t...