In this paper, we define the notion of approximate bisimulation relation between two continuous systems. While exact bisimulation requires that the observations of two systems are and remain identical, approximate bisimulation allows the observations to be different provided the distance between them remains bounded by some parameter called precision. Approximate bisimulation relations are conv...

The fundamental notion of bisimulation has inspired various notions of system equivalences in concurrency theory. Many notions of bisimulation for various discrete systems have been recently unified in the abstract category theoretical formulation of bisimulation due to Joyal, Nielsen and Winskel. In this paper, we adopt their framework and unify the notions of bisimulation equivalences for dis...

We improve on an existing [P.A. Abdulla, J. Högberg, L. Kaati. Bisimulation Minimization of Tree Automata. Int. J. Found. Comput. Sci. 18(4): 699–713, 2007] bisimulation minimization algorithm for finite-state tree automata by introducing backward and forward bisimulation and developing minimization algorithms for them. Minimization via forward bisimulation is also effective on deterministic tr...

Open hedged bisimulation was proposed as a generalisation to the spi calculus of the pi calculus’open bisimulation. In this paper, we extend previous work on open hedged bisimulation. We show that open hedged bisimilarity is closed under respectful substitutions and give a symbolic characterisation of open hedged bisimulation. The latter result is an important step towards mechanisation of open...

A higher-order process calculus is a calculus for communicating systems which contains higher-order constructs like communication of terms. We analyse the notion of bisimulation in these calculi. We argue that both the standard deenition of bisimulation (i.e., the one for CCS and related calculi), as well as higher-order bisimulation AGR88, Bou89, Tho90] are in general unsatisfactory, because o...

Bisimulation quantifiers are a natural extension of modal logics. They preserve the bisimulation invariance of modal logic, while allowing monadic second-order expressivity. Unfortunately, it is not the case that extension by bisimulation quantifiers always preserves the decidability of a modal logic. Here we examine a general class of modal logics for which decidability is preserved under exte...

We present and compare several algorithms for computing the maximal strong bisimulation, the maximal divergence-respecting delay bisimulation, and the maximal divergence-respecting weak bisimulation of a generalised labelled transition system. These bisimulation relations preserve CSP semantics, as well as the operational semantics of programs in other languages with operational semantics descr...

We introduce a new notion of bisimulation, called event bisimulation on labelled Markov processes (LMPs) and compare it with the, now standard, notion of probabilistic bisimulation, originally due to Larsen and Skou. Event bisimulation uses a sub σ-algebra as the basic carrier of information rather than an equivalence relation. The resulting notion is thus based on measurable subsets rather tha...

Refinement in bisimulation semantics is defined differently from refinement in failure semantics: in bisimulation semantics refinement is based on simulations between labelled transition systems, whereas in failure semantics refinement is based on inclusions between failure systems. There exist however pairs of refinements, for bisimulation and failure semantics respectively, that have almost t...

Markov automata (MA) and weak bisimulation have been proposed by Eisentraut, Hermanns and Zhang in [10]. In this paper we propose early and late semantics of Markovian automata, and then introduce early and late weak bisimulations correspondingly. We show that early weak bisimulation coincides with the weak bisimulation in [10], and late weak bisimulation is strictly coarser. Further, we extend...