Results 1  10
of
55
Model Checking for a Probabilistic Branching Time Logic with Fairness
 Distributed Computing
, 1998
"... We consider concurrent probabilistic systems, based on probabilistic automata of Segala & Lynch [55], which allow nondeterministic choice between probability distributions. These systems can be decomposed into a collection of "computation trees" which arise by resolving the nondeterm ..."
Abstract

Cited by 135 (41 self)
 Add to MetaCart
We consider concurrent probabilistic systems, based on probabilistic automata of Segala & Lynch [55], which allow nondeterministic choice between probability distributions. These systems can be decomposed into a collection of "computation trees" which arise by resolving the nondeterministic, but not probabilistic, choices. The presence of nondeterminism means that certain liveness properties cannot be established unless fairness is assumed. We introduce a probabilistic branching time logic PBTL, based on the logic TPCTL of Hansson [30] and the logic PCTL of [55], resp. pCTL of [14]. The formulas of the logic express properties such as "every request is eventually granted with probability at least p". We give three interpretations for PBTL on concurrent probabilistic processes: the first is standard, while in the remaining two interpretations the branching time quantifiers are taken to range over a certain kind of fair computation trees. We then present a model checking algorithm for...
Compositionality for probabilistic automata
 In Proc. 14th International Conference on Concurrency Theory (CONCUR 2003), volume 2761 of LNCS
, 2003
"... x ..."
(Show Context)
Deciding Bisimilarity and Similarity for Probabilistic Processes
, 2000
"... This paper deals with probabilistic and nondeterministic processes represented by a variant of labelled transition systems where any outgoing transition of a state s is augmented with probabilities for the possible successor states. Our main contribution are algorithms for computing the bisimulatio ..."
Abstract

Cited by 39 (4 self)
 Add to MetaCart
This paper deals with probabilistic and nondeterministic processes represented by a variant of labelled transition systems where any outgoing transition of a state s is augmented with probabilities for the possible successor states. Our main contribution are algorithms for computing the bisimulation equivalence classes as introduced by Larsen & Skou [44] and the simulation preorder `a la Segala & Lynch [57]. The algorithm for deciding bisimilarity is based on a variant of the traditional partitioning technique [43, 51] and runs in time O(mn(log m+ log n)) where m is the number of transitions and n the number of states. The main idea for computing the simulation preorder is the reduction to maximum flow problems in suitable networks. Using the method of Cheriyan, Hagerup & Mehlhorn [15] for computing the maximum flow, the algorithm runs in time O((mn 6 +m 2 n 3 )= log n). Moreover, we show that the networkbased technique is also applicable to compute the simulationlike relation...
Assumeguarantee verification for probabilistic systems
, 2009
"... Abstract. We present a compositional verification technique for systems that exhibit both probabilistic and nondeterministic behaviour. We adopt an assumeguarantee approach to verification, where both the assumptions made about system components and the guarantees that they provide are regular sa ..."
Abstract

Cited by 37 (15 self)
 Add to MetaCart
(Show Context)
Abstract. We present a compositional verification technique for systems that exhibit both probabilistic and nondeterministic behaviour. We adopt an assumeguarantee approach to verification, where both the assumptions made about system components and the guarantees that they provide are regular safety properties, represented by finite automata. Unlike previous proposals for assumeguarantee reasoning about probabilistic systems, our approach does not require that components interact in a fully synchronous fashion. In addition, the compositional verification method is efficient and fully automated, based on a reduction to the problem of multiobjective probabilistic model checking. We present asymmetric and circular assumeguarantee rules, and show how they can be adapted to form quantitative queries, yielding lower and upper bounds on the actual probabilities that a property is satisfied. Our techniques have been implemented and applied to several large case studies, including instances where conventional probabilistic verification is infeasible. 1
Generic trace semantics via coinduction
 Logical Methods in Comp. Sci
, 2007
"... Abstract. Trace semantics has been defined for various kinds of statebased systems, notably with different forms of branching such as nondeterminism vs. probability. In this paper we claim to identify one underlying mathematical structure behind these “trace ..."
Abstract

Cited by 35 (10 self)
 Add to MetaCart
(Show Context)
Abstract. Trace semantics has been defined for various kinds of statebased systems, notably with different forms of branching such as nondeterminism vs. probability. In this paper we claim to identify one underlying mathematical structure behind these “trace
Observing Branching Structure through Probabilistic Contexts
 SIAM J. Comput
"... Abstract. Probabilistic automata (PAs) constitute a general framework for modeling and analyzing discrete event systems that exhibit both nondeterministic and probabilistic behavior, such as distributed algorithms and network protocols. The behavior of PAs is commonly defined using schedulers (also ..."
Abstract

Cited by 26 (2 self)
 Add to MetaCart
(Show Context)
Abstract. Probabilistic automata (PAs) constitute a general framework for modeling and analyzing discrete event systems that exhibit both nondeterministic and probabilistic behavior, such as distributed algorithms and network protocols. The behavior of PAs is commonly defined using schedulers (also called adversaries or strategies), which resolve all nondeterministic choices based on past history. From the resulting purely probabilistic structures, trace distributions can be extracted, whose intent is to capture the observable behavior of a PA. However, when PAs are composed via an (asynchronous) parallel composition operator, a global scheduler may establish strong correlations between the behavior of system components and, for example, resolve nondeterministic choices in one PA based on the outcome of probabilistic choices in the other. It is well known that, as a result of this, the (lineartime) trace distribution precongruence is not compositional for PAs. In his 1995 Ph.D. thesis, Segala has shown that the (branchingtime) probabilistic simulation preorder is compositional for PAs. In this paper, we establish that the simulation preorder is, in fact, the coarsest refinement of the trace distribution preorder that is compositional. We prove our characterization result by providing (1) a context of a given PA A, called the tester, which may announce the state of A to the outside world, and (2) a specific global scheduler, called the observer, which ensures that the state information that is announced is actually correct. Now when another PA B is composed with the tester, it may generate the same external behavior as the observer only when it is able to simulate A in the sense that whenever A goes to some state s, B can go to a corresponding state u, from which it may generate the same external behavior. Our result shows that probabilistic contexts together with global schedulers are able to exhibit the branching structure of PAs.
An Introduction to Probabilistic Automata
 Bulletin of the European Association for Theoretical Computer Science
, 2002
"... This paper provides an elementary introduction to the probabilistic automaton (PA) model, which has been developed by Segala. We describe how distributed systems with discrete probabilities can be modeled and analyzed by means of PAs. We explain how the basic concepts for the analysis of nonproba ..."
Abstract

Cited by 19 (0 self)
 Add to MetaCart
This paper provides an elementary introduction to the probabilistic automaton (PA) model, which has been developed by Segala. We describe how distributed systems with discrete probabilities can be modeled and analyzed by means of PAs. We explain how the basic concepts for the analysis of nonprobabilistic automata can be extended to probabilistic systems. In particular, we treat the parallel composition operator on PAs, the semantics of a PA as a set of trace distributions, an extension of the PA model with time and simulation relations for PAs. Finally, we give an overview of various other state based models that are used for the analysis of probabilistic systems.
Probabilistic Temporal Logics via the Modal MuCalculus
 In Foundations of Software Science and Computation Structures (FOSSACS 99
, 1999
"... This paper presents a mucalculusbased modal logic for describing properties of probabilistic labeled transition systems (PLTSs) and develops a modelchecking algorithm for determining whether or not states in finitestate PTLSs satisfy formulas in the logic. The logic is based on the distinction b ..."
Abstract

Cited by 15 (2 self)
 Add to MetaCart
This paper presents a mucalculusbased modal logic for describing properties of probabilistic labeled transition systems (PLTSs) and develops a modelchecking algorithm for determining whether or not states in finitestate PTLSs satisfy formulas in the logic. The logic is based on the distinction between (probabilistic) "systems" and (nonprobabilistic) "observations": using the modal mucalculus, one may specify sets of observations, and the semantics of our logic then enable statements to be made about the measures of such sets at various system states. The logic may be used to encode a variety of probabilistic modal and temporal logics; in addition, the modelchecking problem for it may be reduced to the calculation of solutions to systems of nonlinear equations. 1 Introduction Classical temporallogic model checking [CES86, McM93] provides a basis for automatically checking the correctness of finitestate systems such as hardware designs and communication protocols. In this fram...
Algebraic Theory of Probabilistic and Nondeterministic Processes
 PROCEEDINGS OF THE WORKSHOP
, 2001
"... In this paper we present an algebraic language for the specification of probabilistic and nondeterministic processes, PNAL, which is a probabilistic extension of EPL (Algebraic Theory of Processes, M. Hennessy) that maintains nondeterminism.We have ..."
Abstract

Cited by 14 (0 self)
 Add to MetaCart
In this paper we present an algebraic language for the specification of probabilistic and nondeterministic processes, PNAL, which is a probabilistic extension of EPL (Algebraic Theory of Processes, M. Hennessy) that maintains nondeterminism.We have
Axiomatization of trace semantics for stochastic nondeterministic processes. Quantitative Evaluation of Systems
 In Proceedings of QEST
, 2004
"... We give a complete axiomatization of trace distribution precongruence for probabilistic nondeterministic processes based on a process algebra that includes internal behavior and recursion. The axiomatization is given for two different semantics of the process algebra that are consistent with the alt ..."
Abstract

Cited by 9 (1 self)
 Add to MetaCart
(Show Context)
We give a complete axiomatization of trace distribution precongruence for probabilistic nondeterministic processes based on a process algebra that includes internal behavior and recursion. The axiomatization is given for two different semantics of the process algebra that are consistent with the alternating model of Hansson and the nonalternating model of Segala, respectively. It is shown that the two semantics coincide up to trace distribution precongruence. 1.