Bożena Woźna-Szcześniak

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.

SAT-Based Bounded Model Checking for Weighted Deontic Interpreted Systems

In this paper we present a SAT-based Bounded Model Checking (BMC) method for weighted deontic interpreted systems (i.e., Kripke structures where transitions carry a weight, which is an arbitrary natural number) and properties expressed in the existential fragment of a weighted temporal logic augmented to include knowledge and deontic components (Wectlkd). 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 Wectlkd formulae that is particularly optimized for managing quantitative weighted temporal operators, knowledge operators, and deontic operators, which are typically found in properties of complex multi-agent systems in models of which we assume the possibility that agents may not behave as they are supposed to, and that acting (coordination, negotiation, cooperation, etc.) of agents may cost. We illustrate how the weighted deontic interpreted systems can be applied to the analysis of a variant of the standard bit transmission problem in which an agent may fail to do something it is supposed to do.

Towards SAT-based BMC for LTLK over Interleaved Interpreted Systems

This paper makes two contributions to the verification of multi-agent systems modelled by interleaved interpreted systems. Firstly, the paper presents theoretical underpinnings of the SAT-based bounded model checking (BMC) approach for LTL extended with the epistemic component (LTLK) over interleaved interpreted systems. Secondly, the BMC method has been implemented and tested on several benchmarks for MAS. The preliminary experimental results reveal advantages and disadvantages of our SAT-based BMC for LTLK and show that the method has a significant potential.

SAT-Based BMC for Deontic Metric Temporal Logic and Deontic Interleaved Interpreted Systems

We consider multi-agent systems’ (MASs) modelled by deontic interleaved interpreted systems and we provide a new SAT-based bounded model checking (BMC) method for these systems. The properties of MASs are expressed by means of the metric temporal logic with discrete semantics and extended to include epistemic and deontic operators. The proposed BMC approach is based on the state of the art solutions to BMC. We test our results on a typical MASs scenario: train controller problem with faults.

Two approaches to bounded model checking for linear time logic with knowledge

The paper deals with symbolic approaches to bounded model checking (BMC) for Linear Time Temporal Logic extended with the epistemic component (LTLK), interpreted over Interleaved Interpreted Systems. Two translations of BMC for LTLK to SAT and to operations on BDDs are presented. The translations have been implemented, tested, and compared with each other as well as with another tool on several benchmarks for MAS. Our experimental results reveal advantages and disadvantages of SAT- versus BDD-based BMC for LTLK.

Checking EMTLK Properties of Timed Interpreted Systems Via Bounded Model Checking

We investigate a SAT-based bounded model checking (BMC) method for EMTLK (the existential fragment of the metric temporal logic with knowledge) that is interpreted over timed models generated by timed interpreted systems. In particular, we translate the existential model checking problem for EMTLK to the existential model checking problem for a variant of linear temporal logic (called HLTLK), and we provide a SAT-based BMC technique for HLTLK. We evaluated the performance of our BMC by means of a variant of a timed generic pipeline paradigm scenario and a timed train controller system.

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.

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.

A Translation of the Existential Model Checking Problem from MITL to HLTL

In the paper we propose a translation of the existential model checking problem for timed automata and properties expressible in MITL to the existential model checking problem for HLTL. Such a translation, for example, allows to adopt LTL bounded model checking method for verification of the MITL properties.

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.