Maria Grazia Vigliotti

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Palamidessi has shown that the π-calculus with mixed choice is powerful enough to solve the leader election problem on a symmetric ring of processes. We show that this is also possible in the calculus of Mobile Ambients (MA), without using communication or restriction. Following Palamidessi’s methods, we deduce that there is no encoding satisfying certain(More)
We compare the expressive power of process calculi by studying the problem of electing a leader in a symmetric network of processes. We consider the π-calculus with mixed choice, separate choice and internal mobility, value-passing CCS and Mobile Ambients, together with other ambient calculi (Safe Ambients, the Push and Pull Ambient Calculus and Boxed(More)
Honda and Yoshida showed how to obtain a meaningful equivalence on processes in the asynchronous -calculus using equational theories identifying insensitive processes. We apply their approach to a dialect of Cardelli and Gordon’s Mobile Ambients. The version we propose here is the Push and Pull Ambient Calculus, where the operational semantics is no longer(More)
The Ambient Calculus offers many ways in which processes can interact and be observed. In the context of Levi and Sangiorgi’s Safe Mobile Ambients (SA), the extra co-capabilities required for interaction complicate the fundamental observations. We show that different formulations of barbs lead to the same barbed congruence. We prove this by following Honda(More)
Mobile Ambients (MA) have acquired a fundamental role in modelling mobility in systems with mobile code and mobile devices, and in computation over administrative domains. We present the stochastic version of Mobile Ambients, called Stochastic Mobile Ambients (SMA), where we extend MA with time and probabilities. Inspired by previous models, PEPA and Sπ, we(More)
In biological phenomena like osmosis, the rate of flow of water molecules in or out of biological compartments depends on the solute concentration and on other forces, like hydrostatic pressure. A similar example is the passive transport of ions in and out the cell membrane. In this paper, we address the problem of faithfully modelling these kind of(More)
Two new methodological results are obtained: first, a way to perturb a network into one with a product-form solution for its equilibrium state probabilities, and secondly, a new compositional approach to deriving corresponding response time distributions. The Reversed Compound Agent Theorem (RCAT) is used to construct suitable perturbations in(More)
We study an output-based encoding of the λ-calculus with explicit substitution into the synchronous π-calculus – enriched with pairing – that has its origin in mathematical logic, and show that this encoding respects reduction. We will define the notion of (explicit) head reduction -which encompasses (explicit) lazy reductionand show that the encoding fully(More)