This paper addresses the problem of deening a formal tool to compare the expressive power of diierent concurrent constraint languages. We reene the notion of embedding by adding some \reasonable" conditions, suitable for concurrent frameworks. The new notion, called modular embedding, is used to deene a preorder among these languages, representing diierent degrees of expressiveness. We show tha...

Abstract Real-time applications such as streaming media and voice require encryption algorithms that do not propagate errors and support fast encryption on small blocks. Since IP packets are delivered out-of-order in routed networks it is difficult to synchronize the source and the destination, therefore requiring encryption algorithms to support out-of-order generation of key stream. In this p...

This paper presents the Logical Process Calculus (LPC), a formalism that supports heterogeneous system specifications containing both operational and declarative subspecifications. Syntactically, kPC extends Milner's Calculus of Conmmnicating Systems with operators fl'om the alternation free linear time p calculus (kT#). Semantically, kPC is equipped with a behavioral preorder that generalizes ...

We introduce a notion of real-valued reward testing for probabilistic processes by extending the traditional nonnegative-reward testing with negative rewards. In this richer testing framework, the may and must preorders turn out to be inverses. We show that for convergent processes with finitely many states and transitions, but not in the presence of divergence, the real-reward must-testing pre...

Synopsis. In a cartesian closed category with an initial object and a dominance that classiies it, an intensional notion of approximation between maps |the path relation (c.f. link relation)| is deened. It is shown that if such a category admits strict/upper-closed factorisations then it preorder-enriches (as a cartesian closed category) with respect to the path relation. By imposing further ax...

We prove that testing preorder of De Nicola and Hennessy is preserved by all De Simone process operators. Based on this result we propose an algorithm for generating axiomatisations of testing preorder for arbitrary De Simone process languages. The axiom systems produced by our algorithm are nite and complete for processes with nite behaviour. In order to achieve completeness for a subclass of ...

We consider equivalence relations and preorders complete for various levels of the arithmetical hierarchy under computable, component-wise reducibility. We show that implication in first order logic is a complete preorder for Σ1, the ≤m relation on EXPTIME sets for Σ2 and the embeddability of computable subgroups of (Q,+) for Σ3. In all cases, the symmetric fragment of the preorder is complete ...

This paper studies conflicts from a process-algebraic point of view and shows how they are related to the testing theory of fair testing. Conflicts have been introduced in the context of discrete event systems, where two concurrent systems are said to be in conflict if they can get trapped in a situation where they are waiting or running endlessly, forever unable to complete their common task. ...

We extend the trace semantics for labeled transition systems to a ran-domized model of concurrent computation. The main objective is to obtain a com-positional semantics. The role of a trace in the randomized model is played by a probability distribution over traces, called a trace distribution. We show that the preorder based on trace distribution inclusion is not a precongruence, and we build...

We propose a probabilistic, energy-aware, broadcast calculus for the analysis of mobile ad-hoc networks. The semantics of our model is expressed in terms of Segala’s probabilistic automata driven by schedulers to resolve the nondeterministic choice among the probability distributions over target states. We develop a probabilistic observational congruence and a energy-aware preorder semantics. T...