Lossy channel systems are systems of finite state automata that communicate via unreliable unbounded fifo channels. Today the main open question in the theory of lossy channel systems is whether bisimulation is decidable. We show that bisimulation, simulation, and in fact all relations between bisimulation and trace inclusion are undecidable for lossy channel systems (and for lossy vector addit...

FuTS, state-to-function transition systems are generalizations of labeled transition systems and of familiar notions of quantitative semantical models as continuous-time Markov chains, interactive Markov chains, and Markov automata. A general scheme for the definition of a notion of strong bisimulation associated with a FuTS is proposed. It is shown that this notion of bisimulation for a FuTS c...

Bisimulation is an equivalence relation over Kripke models. It is often claimed, but little argued for, that bisimulation captures a ‘natural’ notion of similarity in epistemic semantics, in the sense that the differences between bisimilar models are, from an epistemic point of view, irrelevant. In this paper we examine three types of arguments pertaining to the view that bisimilar models are ‘...

In this paper we present an abstraction algorithm that produces a finite bisimulation quotient for an autonomous discrete-time linear system. We assume that the bisimulation quotient is required to preserve the observations over an arbitrary, finite number of polytopic subsets of the system state space. We generate the bisimulation quotient with the aid of a sequence of contractive polytopic su...

Probabilistic automata (PA) are a prominent compositional concurrency model. As a way to justify property-preserving abstractions, in the last years, bisimulation relations over probability distributions have been proposed both in the strong and the weak setting. Different to the usual bisimulation relations, which are defined over states, an algorithmic treatment of these relations is inherent...

We will briefly describe the recently implemented hyperset approach to semi-structured or Web-like and possibly distributed databases with the query system available online at http://www.csc. liv.ac.uk/~molyneux/t/. As this approach is crucially based on the bisimulation relation, the main stress in this paper is on its computation in the distributed case by using a so called bisimulation engin...

We study several techniques for interactive equational reasoning with the bisimulation equivalence. Our work is based on a modular library, formalised in Coq , that axiomatises weakly final coalgebras and bisimulation. As a theory we derive some coalgebraic schemes and an associated coinduction principle. This will help in interactive proofs by coinduction, modular derivation of congruence and ...

Higher-order process calculi have been receiving much attention in recent years for its significance in both theorey and practice. Work on bisimulations has never ceased evolving, typically represented by Thomsen and Sangiorgi for their work on bisimulation theory and encoding to and from first-order process calculi. Fu puts forth linear higher-order π-calculus, and makes improvement to previou...

We address the problem of reducing the size of (nondeterministic, bottom-up) tree automata using suitable, language-preserving equivalences on the states of the automata. In particular, we propose the so-called composed bisimulation as a new language preserving equivalence. Composed bisimulation is defined in terms of two different relations, namely upward and downward bisimulation. Moreover, w...

One way to understand an interactive system is firmly rooted in language theory, that a system is its set of runs (or words). Properties of systems are described in a linear time temporal logic. Relationships between automata, language theory and logic are then utilised, such as the theory of ω-regular languages and Büchi automata. An alternative viewpoint is that an interactive system should b...