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A Road Map of Interval Temporal Logics and Duration Calculi
, 2004
"... We survey main developments, results, and open problems on interval temporal logics and duration calculi. We present various formal systems studied in the literature and discuss their distinctive features, emphasizing on expressiveness, axiomatic systems, and (un)decidability results. ..."
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Cited by 23 (12 self)
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We survey main developments, results, and open problems on interval temporal logics and duration calculi. We present various formal systems studied in the literature and discuss their distinctive features, emphasizing on expressiveness, axiomatic systems, and (un)decidability results.
Model-checking of specifications integrating processes, data and time
, 2005
"... Abstract. We present a new model-checking technique for CSP-OZ-DC, a com-bination of CSP, Object-Z and Duration Calculus, that allows reasoning about systems exhibiting communication, data and real-time aspects. As intermediate layer we will use a new kind of timed automata that preserve events and ..."
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Cited by 18 (3 self)
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Abstract. We present a new model-checking technique for CSP-OZ-DC, a com-bination of CSP, Object-Z and Duration Calculus, that allows reasoning about systems exhibiting communication, data and real-time aspects. As intermediate layer we will use a new kind of timed automata that preserve events and data variables of the specification. These automata have a simple operational seman-tics that is amenable to verification by a constraint-based abstraction-refinement model checker. By means of a case study, a simple elevator parameterised by the number of floors, we show that this approach admits model-checking parame-terised and infinite state real-time systems. 1
Some progress in satisfiability checking for difference logic
- In FORMATS/FTRTFT
, 2004
"... Abstract. In this paper we report a new SAT solver for difference logic, a propositional logic enriched with timing constraints. The main novelty of our solver is a tighter integration of the incremental analysis of numerical conflicts with the process of Boolean conflict analysis. This and other im ..."
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Cited by 16 (2 self)
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Abstract. In this paper we report a new SAT solver for difference logic, a propositional logic enriched with timing constraints. The main novelty of our solver is a tighter integration of the incremental analysis of numerical conflicts with the process of Boolean conflict analysis. This and other improvements lead to significant performance gains for some classes of problems. 1
Efficient SAT engines for concise logics: Accelerating proof search for zero-one linear constraint systems
, 2003
"... We investigate the problem of generalizing acceleration techniques as found in recent satisfiability engines for conjunctive normal forms (CNFs) to linear constraint systems over the Booleans. The rationale behind this research is that rewriting the propositional formulae occurring in e.g. bounded m ..."
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Cited by 8 (4 self)
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We investigate the problem of generalizing acceleration techniques as found in recent satisfiability engines for conjunctive normal forms (CNFs) to linear constraint systems over the Booleans. The rationale behind this research is that rewriting the propositional formulae occurring in e.g. bounded model checking (BMC) [5] to CNF requires a blowup in either the formula size (worst-case exponential) or in the number of propositional variables (linear, thus yielding a worst-case exponential blow-up of the search space). We demonstrate that acceleration techniques like observation lists and lazy clause evaluation [14] as well as the more traditional non-chronological backtracking and learning techniques generalize smoothly to Davis-Putnam-like resolution procedures for the very concise propositional logic of linear constraint systems over the Booleans. Despite the more expressive input language, the performance of our prototype implementation comes surprisingly close to that of state-of-the-art CNF-SAT engines like ZCha [14]. First experiments with bounded model-construction problems show that the overhead in the satisfiability engine that can be attributed to the richer input language is often amortized by the conciseness gained in the propositional encoding of the BMC problem.
A Theory of Duration Calculus with Application
"... Abstract. In this chapter we will present selected central elements in the theory of Duration Calculus and we will give examples of applications. The chapter will cover syntax, semantics and proof system for the basic logic. Furthermore, results on decidability, undecidability and model-checking wil ..."
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Cited by 5 (0 self)
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Abstract. In this chapter we will present selected central elements in the theory of Duration Calculus and we will give examples of applications. The chapter will cover syntax, semantics and proof system for the basic logic. Furthermore, results on decidability, undecidability and model-checking will be presented. A few extensions of the basic calculus will be described, in particular, Hybrid Duration Calculus and Duration Calculus with iterations. Furthermore, a case study: the bi-phase mark protocol, is presented. We will not attempt to be exhaustive in our coverage of topics; but we will provide references for further study. Keywords: Real-time systems, metric-time temporal logic, duration calculus, decidability, model-checking, application 1 Introduction to Duration Calculus In this chapter we will introduce Durations Calculus (abbreviated DC) [72], present central elements of the theory, and show examples of applications. The aim is not to make a comprehensive presentation of the logic; but rather to cover
Symbolic Test Case Generation for Time-Discrete Hybrid Systems
"... In this article we present a model-based test case specification and associated test data generation methods for embedded systems processing Boolean, integral and real-valued variables. Testing experts are relieved from the task of constructing input data to the system under test in an explicit way ..."
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In this article we present a model-based test case specification and associated test data generation methods for embedded systems processing Boolean, integral and real-valued variables. Testing experts are relieved from the task of constructing input data to the system under test in an explicit way and manually calculating the expected reactions. Instead, test cases are specified by means of temporal logic formulae using the Duration Calculus, allowing to describe classes of concrete runs which are considered equivalent for the test objectives to be investigated. The concrete input data to the system under test and its expected reactions are automatically generated using an approach based on interval analysis. Following this approach, test data generation is handled as an interval constraint solving problem. The basic solution technique based on pavings of the solution set and bi-partitioning algorithms are accelerated by using a tightly integrated combination of interval constraint propagation and a variety of novel techniques originating from Boolean SAT solving methods, which have been adapted for the mixed Boolean, integer and real-valued variable setting. 1
On Sampling Abstraction of Continuous Time Logic with Durations
"... Abstract. Duration Calculus (DC) is a real-time logic with measurement of duration of propositions in observation intervals. It is a highly expressive logic with continuous time behaviours (also called signals) as its models. Validity checking of DC is undecidable. We propose a method for validity c ..."
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Abstract. Duration Calculus (DC) is a real-time logic with measurement of duration of propositions in observation intervals. It is a highly expressive logic with continuous time behaviours (also called signals) as its models. Validity checking of DC is undecidable. We propose a method for validity checking of Duration Calculus by reduction to a sampled time version of this logic called well sampled Interval Duration Logic (WSIDL). This reduction relies on representing a continuous time behaviour by a well-sampled behaviour with 1-oversampling. We provide weak and strong reductions (abstractions) of logic DC to logic WSIDL which respectively preserve the validity and the counter examples. By combining these reductions with previous work on deciding IDL, we implement a tool for validity checking of Duration Calculus. This provides a partial but practical method for validity checking of Duration Calculus. We present some preliminary experimental results to measure the success of this approach. 1
