scholarly journals STAMINA: STochastic Approximate Model-Checker for INfinite-State Analysis

2019 ◽  
pp. 540-549 ◽  
Author(s):  
Thakur Neupane ◽  
Chris J. Myers ◽  
Curtis Madsen ◽  
Hao Zheng ◽  
Zhen Zhang
Keyword(s):  
Approximate Model ◽  
Model Checker ◽  
Infinite State ◽  
State Analysis

SMT-based verification of data-aware processes: a model-theoretic approach

2020 ◽  
Vol 30 (3) ◽  
pp. 271-313
Author(s):  
Diego Calvanese ◽  
Silvio Ghilardi ◽  
Alessandro Gianola ◽  
Marco Montali ◽  
Andrey Rivkin
Keyword(s):  
Model Theory ◽  
Satisfiability Modulo Theories ◽  
Theoretic Approach ◽  
Model Checker ◽  
Present Contribution ◽  
Relational Systems ◽  
Infinite State Systems ◽  
Algorithmic Techniques ◽  
The One ◽  
Infinite State

AbstractIn recent times, satisfiability modulo theories (SMT) techniques gained increasing attention and obtained remarkable success in model-checking infinite-state systems. Still, we believe that whenever more expressivity is needed in order to specify the systems to be verified, more and more support is needed from mathematical logic and model theory. This is the case of the applications considered in this paper: we study verification over a general model of relational, data-aware processes, to assess (parameterized) safety properties irrespectively of the initial database (DB) instance. Toward this goal, we take inspiration from array-based systems and tackle safety algorithmically via backward reachability. To enable the adoption of this technique in our rich setting, we make use of the model-theoretic machinery of model completion, which surprisingly turns out to be an effective tool for verification of relational systems and represents the main original contribution of this paper. In this way, we pursue a twofold purpose. On the one hand, we isolate three notable classes for which backward reachability terminates, in turn witnessing decidability. Two of such classes relate our approach to conditions singled out in the literature, whereas the third one is genuinely novel. On the other hand, we are able to exploit SMT technology in implementations, building on the well-known MCMT (Model Checker Modulo Theories) model checker for array-based systems and extending it to make all our foundational results fully operational. All in all, the present contribution is deeply rooted in the long-standing tradition of the application of model theory in computer science. In particular, this paper applies these ideas in an original mathematical context and shows how these techniques can be used for the first time to empower algorithmic techniques for the verification of infinite-state systems based on arrays, so as to make such techniques applicable to the timely, challenging settings of data-aware processes.

scholarly journals INFAMY: An Infinite-State Markov Model Checker

2009 ◽  
pp. 641-647 ◽  
Author(s):  
Ernst Moritz Hahn ◽  
Holger Hermanns ◽  
Björn Wachter ◽  
Lijun Zhang
Keyword(s):  
Markov Model ◽  
Model Checker ◽  
Infinite State

scholarly journals A Multistep Extending Truncation Method towards Model Construction of Infinite-State Markov Chains

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Kemin Wang ◽  
Yongbin Wang ◽  
Zhengtao Jiang ◽  
Wenlong Fu
Keyword(s):  
Model Checking ◽  
Markov Chains ◽  
Continuous Time ◽  
Model Construction ◽  
Model Checker ◽  
State Explosion ◽  
Truncation Method ◽  
Continuous Time Markov Chains ◽  
System Properties ◽  
Infinite State

The model checking of Infinite-State Continuous Time Markov Chains will inevitably encounter the state explosion problem when constructing the CTMCs model; our method is to get a truncated model of the infinite one; to get a sufficient truncated model to meet the model checking of Continuous Stochastic Logic based system properties, we propose a multistep extending advanced truncation method towards model construction of CTMCs and implement it in the INFAMY model checker; the experiment results show that our method is effective.

scholarly journals Implicit Semi-Algebraic Abstraction for Polynomial Dynamical Systems

2021 ◽  
pp. 529-551
Author(s):  
Sergio Mover ◽  
Alessandro Cimatti ◽  
Alberto Griggio ◽  
Ahmed Irfan ◽  
Stefano Tonetta
Keyword(s):  
Dynamical Systems ◽  
Discrete Systems ◽  
Model Checker ◽  
Safety Verification ◽  
Polynomial Dynamical Systems ◽  
Main Challenge ◽  
Safety Property ◽  
Verification Problem ◽  
Explicit Enumeration ◽  
Infinite State

AbstractSemi-algebraic abstraction is an approach to the safety verification problem for polynomial dynamical systems where the state space is partitioned according to the sign of a set of polynomials. Similarly to predicate abstraction for discrete systems, the number of abstract states is exponential in the number of polynomials. Hence, semi-algebraic abstraction is expensive to explicitly compute and then analyze (e.g., to prove a safety property or extract invariants).In this paper, we propose an implicit encoding of the semi-algebraic abstraction, which avoids the explicit enumeration of the abstract states: the safety verification problem for dynamical systems is reduced to a corresponding problem for infinite-state transition systems, allowing us to reuse existing model-checking tools based on Satisfiability Modulo Theory (SMT). The main challenge we solve is to express the semi-algebraic abstraction as a first-order logic formula that is linear in the number of predicates, instead of exponential, thus letting the model checker lazily explore the exponential number of abstract states with symbolic techniques. We implemented the approach and validated experimentally its potential to prove safety for polynomial dynamical systems.

Declarative Parameterized Verification of Distributed Protocols via the Cubicle Model Checker

2021 ◽  
Vol 178 (4) ◽  
pp. 347-378
Author(s):  
Sylvain Conchon ◽  
Giorgio Delzanno ◽  
Angelo Ferrando
Keyword(s):  
A Priori ◽  
Asynchronous Communication ◽  
Model Checker ◽  
Distributed Objects ◽  
Distributed Protocols ◽  
Parameterized Verification ◽  
Verification Tools ◽  
Transition Rules ◽  
Update Rules ◽  
Infinite State

We show that Cubicle, an SMT-based infinite-state model checker, can be applied as a verification engine for GLog, a logic-based language based on relational updates rules that has been applied to specify topology-sensitive distributed protocols with asynchronous communication. In this setting, the absence of protocol anomalies can be reduced to a coverability problem in which the initial set of configurations is not fixed a priori (Existential Coverability Problem). Existential Coverability in GLog can naturally be expressed into Parameterized Verification judgements in Cubicle. The encoding is based on a translation of relational update rules into transition rules that modify cells of unbounded arrays. To show the effectiveness of the approach, we discuss several verification problems for distributed protocols and distributed objects, a challenging task for traditional verification tools. The experimental results show the flexibility and robustness of Cubicle for the considered class of protocol examples.

Valence state analysis of elements by EPMA and its application

1990 ◽  
Vol 48 (2) ◽  
pp. 230-231
Author(s):  
Chen Liqing ◽  
Liu Zuqin ◽  
Zhang Wei
Keyword(s):  
Valence State ◽  
Line Intensities ◽  
Valence States ◽  
Valence Electrons ◽  
Fe And Mn ◽  
Intensity Ratios ◽  
State Analysis

Valence state analyses of Fe and Mn in oxides by EPMA have been reported in literature. In this paper, the effects of valence state on intensity ratios ILα/IKα and ILα/ILβ of Cu, Ni, Co, Fe, Mn, Cr and their oxides, and on intensity ratios ILβ2/ILα1 and ILγ1/ILα1 of Mo, Nb, Zr and their oxides were studied. It was observed that intensity ratios change with valence states in accordance with some regularities, and these effects could be utilized for analyzing the valence states of catalysts.Valence state analysis of elements by EPMA is based on the fact that changes in the states of valence electrons in the outer shells of an atom cause corresponding changes in line intensities. The M electrons of Cu, Ni, Co, Fe, Mn, Cr and the N electrons of Mo, Nb, Zr are valence electrons. Line Kα1,2 and six lines of L are produced from the transitions of K-L2,3 and L-M or L-N respectively.

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