This article introduces a fully automated verification technique that permits to analyze real-time systems described using a continuous notion of time and a mixture of operational (i.e., automata-based) and descriptive (i.e., logic-based) formalisms. The technique relies on the reduction, under reasonable assumptions, of the continuous-time verification problem to its discrete-time counterpart. This reconciles in a viable and effective way the dense/discrete and operational/descriptive dichotomies that are often encountered in practice when it comes to specifying and analyzing complex critical systems. The article investigates the applicability of the technique through a significant example centered on a communication protocol. More precisely, concurrent runs of the protocol are formalized by parallel instances of a Timed Automaton, while the synchronization rules between these instances are specified through Metric Temporal Logic formulas, thus creating a multi-paradigm model. Verification tests run on

The goal of this project is to extend the domain of applicability of formal verification methodology from functional design toward more lower-level performance sensitive design. We intend to develop new methods for circuit timing analysis based on the timed automaton model while taking special care of the scalability requirements implied by the size of industrial-size circuits. We hope that such methods will give better results than static timing analysis methods which are currently in use, and that they could be applied beyond the scope of these methods, for example, to cyclic circuits. 1 1

Abstract: Probabilistic timed automata can be used to model systems in which probabilistic and timing behavior coexist. Verification of probabilistic timed automata models is generally performed with regard to a single reference valuation of the timing parameters. Given such a parameter valuation, we present a method for obtaining automatically a constraint on timing parameters for which the reachability probabilities (1) remain invariant and (2) are equal to the reachability probabilities for the reference valuation. The method relies on parametric analysis of a nonprobabilistic version of the probabilistic timed automata model using the “inverse method”. Our approach is useful for avoiding repeated executions of probabilistic model checking analyses for the same model with different parameter valuations. We provide examples of the application of our technique to models of randomized protocols.

This paper revisits the classical notion of sampling in the setting of real-time temporal logics for the modeling and analysis of systems. The relationship between the satisfiability of Metric Temporal Logic (MTL) formulas over continuous-time models and over discrete-time models is studied. It is shown to what extent discrete-time sequences obtained by sampling continuous-time signals capture the semantics of MTL formulas over the two time domains. The main results apply to “flat ” formulas that do not nest temporal operators and can be applied to the problem of reducing the verification problem for MTL over continuous-time models to the same problem over discrete-time, resulting in an automated partial practically-efficient discretization technique.

1.2 Modeling with timed and hybrid automata................... 3