Tamás Tóth

Algorithms and protocols with time dependent behavior are often specified formally using timed automata. For practical real-time systems, besides real-valued clock variables, these specifications typically contain discrete data variables with nontrivial data flow. In this paper, we propose a configurable lazy abstraction framework for the location...

Systems and software with time dependent behavior are often formally specified using timed automata. For practical real-time systems, these specifications typically contain discrete data variables with nontrivial data flow besides real-valued clock variables. In this paper, we propose a lazy abstraction method for the location reachability problem...

In this paper, we present THETA, a configurable model checking framework. The goal of the framework is to support the design, execution and evaluation of abstraction refinement-based reachability analysis algorithms for models of different formalisms. It enables the definition of input formalisms , abstract domains, model interpreters, and strategi...

Formal verification techniques are widely used for detecting design flaws in software systems. Formal verification can be done by transforming an already implemented source code to a formal model and attempting to prove certain properties of the model (e.g. that no erroneous state can occur during execution). Unfortunately, transformations from sou...

To solve the reachability problem for timed automata, model checkers usually apply forward search and zone abstraction. To ensure efficiency and termination, the computed zones are generalized using maximal constants obtained from guards either by static analysis or lazily for a given path. In this paper, we propose a lazy method based on zone abst...

The behavior of practical safety critical systems often combines real-time behavior with structured data flow. To ensure correctness of such systems, both aspects have to be modeled and formally verified. Time related behavior can be efficiently modeled and analyzed in terms of timed automata. At the same time, program verification techniques like...

Statecharts are frequently used as a modeling formalism in the design of state-based systems. Formal verification techniques are also often applied to prove certain properties about the behavior of the system. One of the most efficient techniques for formal verification is Counterexample-Guided Abstraction Refinement (CEGAR), which reduces the comp...

Correctness of software components in a distributed system is a key issue to ensure overall reliability. Formal verification techniques such as model checking can show design flaws at early stages of development. Abstraction is a key technique for reducing complexity by hiding information, which is not relevant for verification. Counterexample-Guid...

Formal methods, especially model checking techniques, are often used for the verification of the resilience of safety critical systems. The usual complexity of the verification problem in real life systems (due to state space explosion and the handling of time dependent behavior) demands efficient techniques. In this paper we propose a decompositio...

Formal methods have an important role in ensuring the correctness of safety critical systems. However, their application in industry is always cumbersome: the lack of experts and the complexity of formal languages prevents the efficient application of formal verification techniques. In this paper we take a step in the direction of making formal mod...

Nowadays, safety critical systems are often complex, real-time systems requiring formal methods to prove the correctness of their behavior. This work presents a framework that supports modeling and model checking such systems. We adapted an existing formalism to provide better modeling and model checking support. Using this formalism, we extended a...