Agnieszka M. Zbrzezny

SAT-Based Bounded Model Checking for Weighted Interpreted Systems and Weighted Linear Temporal Logic

We present a SAT-based bounded model checking (BMC) method for the weighted interpreted systems (i.e. interpreted systems augmented to include a weight function, one per each agent, that associates weights with actions, which are arbitrary natural numbers) and for properties expressible in the existential fragment of a weighted linear temporal logic with epistemic components (WELTLK). Since in BMC we translate both the system model and the checked specification to a propositional formula that is later analysed by a SAT-solver, we report on a propositional encoding of both the weighted interpreted systems and the WELTLK formulae. This encoding is designed specifically for managing weighted temporal operators and knowledge operators, which are commonly found in properties of multi-agent systems in models of which we assume that acting of agents may cost. We implemented the proposed BMC algorithm as a new module of VerICS, and we evaluated it by means of the following two examples: a weighted generic pipeline paradigm and a weighted bits transmission problem.

The BMC method for the existential part of RTCTLK and interleaved interpreted systems

In the paper, we focus on the formal verification of multi-agent systems - modelled by interleaved interpreted systems - by means of the bounded model checking (BMC) method, where specifications are expressed in the existential fragment of the Real-Time Computation Tree Logic augmented to include standard epistemic operators (RTECTLK). In particular, we define an improved SAT-based BMC for RTECTLK, and present performance evaluation of our newly developed BMC method by means of the well known train controller and generic pipeline systems.

Bounded Model Checking for Weighted Interpreted Systems and for Flat Weighted Epistemic Computation Tree Logic

The paper deals with the SAT- and ROBDD-based bounded model checking (BMC) methods for the existential fragment of a flat weighted epistemic computation tree logic (FWECTLK) interpreted over weighted interpreted systems. We implemented the both BMC algorithms, and compared them with each other on several benchmarks for multi-agent systems.

Efficient Model Checking Timed and Weighted Interpreted Systems Using SMT and SAT Solvers

In this paper we define Satisfiability Modulo Theory based (SMT-based) and SAT-based bounded model checking (BMC) methods for the existential fragment of Weighted Epistemic Linear Time Logic (WLTLK) interpreted on Timed Weighted Interpreted Systems (TWISs). We provide an implementation based on Z3 and PicoSAT solvers and we present a comparison of the two methods on common instances that can be scaled up to for performance evaluation. A detailed analysis of results shows that in many instances the SMT-based approach can be significantly faster than the SAT-based approach.

SMT-Based Bounded Model Checking for Weighted Epistemic ECTL

We define the SMT-based bounded model checking (BMC) method for weighted interpreted systems and for the existential fragment of the weighted epistemic computation tree logic. We implemented the new BMC algorithm and compared it with the SAT-based BMC method for the same systems and the same property language on several benchmarks for multi-agent systems.

Checking WECTLK Properties of Timed Real-Weighted Interpreted Systems via SMT-Based Bounded Model Checking

In this paper, we present the SMT-based bounded model checking (BMC) method for Timed Real-Weighted Interpreted Systems and for the existential fragment of the Weighted Epistemic Computation Tree Logic. We performed the BMC algorithm on Timed Weighted Generic Pipeline Paradigm benchmark. We have implemented SMT-BMC method and made preliminary experimental results, which demonstrate the efficiency of the method. To perform the experiments we used the state of the art SMT-solver Z3.

SAT-Based Bounded Model Checking for RTECTL and Simply-Timed Systems

We report on a SAT-based bounded model checking (BMC) method for simply-timed systems (i.e., Kripke models where transitions carry a duration, which is an arbitrary natural number) generated by simply-timed automata with discrete data, and properties expressed in the existential fragment of a soft real-time temporal logic (RTECTL). In particular, since in BMC both the system model and the checked property are translated into a Boolean formula to be analysed by a SAT-solver, we introduce a new Boolean encoding of the RTECTL formulae that is particularly optimized for managing quantitative metric temporal operators, typically found in properties of soft real-time systems (simply-timed systems). The proposed BMC algorithm is implemented as a new module of VerICS, and evaluated by means of two scalable scenarios.

Checking WELTLK Properties of Weighted Interpreted Systems via SMT-Based Bounded Model Checking

We present a SMT-based bounded model checking (BMC) method for weighted interpreted systems (i.e. interpreted systems in which every agent includes a weight function that associates with each local action a weight, which is an arbitrary natural number) and for properties expressible in the existential fragment of a weighted linear temporal logic with epistemic components (WELTLK). We implemented the standard BMC algorithm and compared it with the SAT-based BMC method for the same systems and the same property language on two multi-agent systems: a weighted bit transmission problem and a weighted generic pipeline paradigm. For the SAT-based BMC we used the PicoSAT solver and for the SMT-based BMC we used the Z3 solver.

Two Approaches to Bounded Model Checking for a Soft Real-Time Epistemic Computation Tree Logic

We tackle two symbolic approaches to bounded model checking (BMC) for an existential fragment of the soft real-time epistemic computation tree logic (RTECTLK) interpreted over interleaved interpreted systems. We describe a BDD-based BMC method for RTECTLK, and provide its experimental evaluation and comparison with a SAT-based BMC method. Moreover, we have attempted a comparison with MCMAS on several benchmarks.

Simple Bounded MTLK Model Checking for Timed Interpreted Systems

We present a new translation of Metric Temporal Logic with knowledge operators (MTLK) to the Linear Temporal Logic with knowledge operators and with a new set of the atomic propositions (\({\mathrm{{\mathrm{{LTL}}}}_\mathrm{q}\mathrm {K}}\)). We investigate a SAT-based bounded model checking (BMC) method for MTLK. The semantics of MTLK is defined over timed interpreted systems (TIS). We show how to implement the bounded model checking technique for \({\mathrm{{\mathrm{{LTL}}}}_\mathrm{q}\mathrm {K}}\) and timed interpreted systems, and as a case study, we apply the technique in the analysis of the Timed Generic Pipeline Paradigm modelled by TIS. We also present the differences between the old translation of MTLK and the new one. The theoretical description is supported by the experimental results that demonstrate the efficiency of the method.