This paper explores the connection between semantic equivalences for concrete sequential processes, represented by means of transition systems, and formats of transition system speciications using Plotkin's structural approach. For several equivalences in the linear time { branching time spectrum a format is given, as general as possible, such that this equivalence is a congruence for all opera...

A hybrid automaton is a formalmodel for a mixed discrete-continuous system. We classify hybrid automata acoording to what questions about their behavior can be answered algorithmically. The classi cation reveals structure on mixed discrete-continuous state spaces that was previously studied on purely discrete state spaces only. In particular, various classes of hybrid automata induce nitary tra...

Precise translation from hybrid models to code is difficult because models are defined in the continuous-time domain whereas code executes on digital computers in a discrete fashion. Traditional approach is to associate the model with a sampling rate before code generation, and rely on an approximate algorithm that computes the next state numerically. Depending on the choice of the sampling rat...

Following and expanding upon the philosophy set down by Cousot and Cousot, this tutorial paper uses stepwise abstract interpretation to transform a system’s naive trace-set semantics into a format that is readily analyzable by temporal logic. The abstraction interpretations first transform a concrete trace-set semantics, where the traces are characterized by a state-transition relation, into an...

Contextual equivalences for cryptographic process calculi, like the spi-calculus, can be used to reason about correctness of protocols, but their definition suffers from quantification over all possible contexts. Here, we focus on two such equivalences, namely may-testing and barbed equivalence, and investigate tractable proof methods for them. To this aim, we design an enriched labelled transi...

We investigate logics for coalgebraic simulation from a compositional perspective. Specifically, we show that the expressiveness of an inductively-defined language for coalgebras w.r.t. a given notion of simulation comes as a consequence of an expressivity condition between the language constructor used to define the language for coalgebras, and the relator used to define the notion of simulati...

background: cigarette smoking is one of the most important health‑related risk factors in terms of morbidity and mortality. in this study, we introduced a new method for deriving the transitional probabilities of smoking stages from a cross‑sectional study and simulated a long‑term smoking behavior for adolescents. methods: in this study in 2010, a total of 4853 high school students were random...

In this paper, we present a conformance testing theory for Barbosa’s abstract components. We do so by defining a trace model for components from causal transfer functions which operate on data flows at discrete instants. This allows us to define a test selection strategy based on test purposes which are defined as subtrees of the execution tree built from the component traces. Moreover, we show...