R. Alur, T. Feder, and T. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116 -- 146, 1996.  Home/Search   Document Details and Download   Summary   Related Articles   Check

...., and show that timed games with winning conditions expressed by TCTL formulas are undecidable. This result is quite expected since it is already known that equality makes the satisfiability problem for TCTL undecidable [2] The same was also observed for the linear time temporal logic MITL [4]. Moreover, our undecidability result is closely related to the one recently proved for the TCTL module checking [18] There, the authors give a direct reduction from the problem of deciding if a nondeterministic two counter machine has a recurring computation (i.e. the starting state is visited ....

R. Alur, T. Feder, and T. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116 -- 146, 1996.

....self monitoring code which may be run both on the simulation level and on the code level. We discuss our approach in its full details through an example on a SONY AIBO robotic dog. 1 Introduction Automatic code generation from hybrid automaton models attracts much research interest recently [14,15,5] Besides the significant cut of the development cost, the benefits of automatic code generation also include that the system can be verified on the model level and the generated code can be free of human errors which otherwise may be introduced by manual translation. Recently, code ....

....code can be free of human errors which otherwise may be introduced by manual translation. Recently, code generation from hybrid system models has been used for embedded systems. Industry has followed the trend by providing their own tools This research was supported in part by NSF CCR 9988409, NSF CCR 0086147, NSF CCR 0209024, ARO DAAD19 01 1 0473, and DARPA ITO MOBIES F33615 00 C 1707. Email: tanli,jesung saul.cis.upenn.edu Email: lee cis.upenn.edu c #2003 Published by Elsevier Science B. V. environment constraints testing goal coverage checker simulator code ....

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R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. In Journal of the ACM, volume 43, pages 116--146, 1999.

.... There are algorithms for simple cases (where decidability holds) which visit the graph of regions, where regions encapsulate infinite evaluations ( 8] 16] and [35] A di#erent way to obtain decidability is to relax punctuality, i.e. it is not permitted to consider singleton intervals (see [15] and [67] Also for the mentioned logics, symbolic model checking methods ( 16] and [8] are proposed. In order to make checking easier, di#erent abstractions are considered: substitutions (see [79] bisimulation (see [19] and use of discrete time domain as an approximation for the dense time ....

....exponential w.r.t. n. ## a 1 , x # = 0 x = 1, a 2 1, a 2 Figure 6.2: The role of punctuality ## Figure 6. 3: The automaton H ( a 1 ,I 1 ) h) a 2 ,I 2 ) #) The third reason is that the decidable classes of TPTL do not admit punctuality (see [67] and [15]) which is useful in our setting. As an example, let H be the automaton in Fig.6.2. We note that H # (a 1 , time [1, 1] #, which means that if a 2 is performed exactly one time unit after a 1 , then b has been performed in the meantime. This is an information flow, which cannot be ....

Alur, R., Henzinger, T. A.: The benefits of relaxing punctuality. The Journal of the ACM 43 (1996), 116--146.

....in which the constraints on the current state are separated from the constraints on the future states. In the real time domain, tableau constructions have been developed for various logics and their complexities have been studied [2, 10] For dense time linear temporal logic the algorithms of [2, 4] and [8] are (to the best of the author s knowledge) the only existing tableau constructions to date. 2, 4] being aimed at establishing a theoretical connection between temporal logic and timed automata and [8] a first attempt at a practical algorithm suitable for model checking. 1] describes ....

....In the real time domain, tableau constructions have been developed for various logics and their complexities have been studied [2, 10] For dense time linear temporal logic the algorithms of [2, 4] and [8] are (to the best of the author s knowledge) the only existing tableau constructions to date. [2, 4] being aimed at establishing a theoretical connection between temporal logic and timed automata and [8] a first attempt at a practical algorithm suitable for model checking. 1] describes the construction of so called testing automata from formulas in a safety modal logic for the Uppaal tool. The ....

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R. Alur, T. Feder, and T. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116--146, January 1996.

....both theoretically and practically, in formulating various A short version [19] of this paper appears in the Proceedings of the 13th International Conference on Computer aided Verification (CAV 01) Lecture Notes in Computer Science 2102, pp. 506 517, Springer. timed temporal logics [2, 4 6, 27, 32, 34, 35] and developing verification tools [11, 26, 30] Region reachability is useful but has intrinsic limitations. In many real world applications [14] we might also want to know whether a timed automaton satisfies a non region property; e.g. for two given states s and s x 1 2x 2 x 3 x ....

R. Alur, T. Feder, and T. A. Henzinger, "The benefits of relaxing punctuality," J. ACM, 43 (1996) 116-146 28

....in the model and those in the realization. 1 Introduction Over the past decades, we have witnessed a significant increase in the application of formal techniques to the design of real time systems. Various studies have been carried out in the advance of real time property verification techniques [2, 3, 11, 10] and their applications [9, 13] These real time properties are formal representations of timing requirements in a realization, whose behaviour is abstracted in the corresponding model. Typically, timed systems and metric interval temporal logic (MITL) 3] have been used to formalize behaviour and ....

....verification techniques [2, 3, 11, 10] and their applications [9, 13] These real time properties are formal representations of timing requirements in a realization, whose behaviour is abstracted in the corresponding model. Typically, timed systems and metric interval temporal logic (MITL)[3] have been used to formalize behaviour and timing requirements respectively and have achieved success in yielded a wide range of realtime systems. # This research is supported by PROGRESS, the embedded systems research program of the Dutch organisation for Scientific Research NWO, the Dutch ....

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R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116--146, 1996.

....properties are fundamental for the correctness of realtime systems, a number of real time extensions of temporal and modal logics have been proposed over the past few years. There are three main approaches for extending both linear time and branching time temporal logics. ffl Bounded operators [31, 3, 8, 6, 63, 76] The idea is of replacing the classical temporal operators by time bounded operators. The operator 3 [2;4] is interpreted as eventually within 2 and 4 units of time. For instance, the bounded response property is expressed by the formula A2(p oe A3 [0;3] q) in a branching time framework. ffl ....

....in classical transition systems clocks and clock constraint. However the model checking is not decidable for arbitrary real time logics. In the case of linear time logics the model checking is decidable over discrete time and also over dense time, if the logic cannot express punctuality properties [7, 8, 6]. On the other hand, for branching time temporal logics model checking of punctuality properties is possible even over a dense time domain [3, 2, 45] However, in this case it is necessary to consider constraints over time that do not contain addition of variables. Proof rules for checking bounded ....

R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. In Proceedings of the Tenth Annual Symposium on Principles of Distributed Computing, pages 139--152. ACM Press, 1991.

.... for recent surveys) In particular, by using the standard region technique, it has been shown that region reachability for timed automata is decidable [3] This fundamental result and the technique help researchers, both theoretically and practically, in formulating various timed temporal logics [2, 4 6, 27, 32 34] and developing verification tools [11, 26, 30] Region reachability is useful but has intrinsic limitations. In many real world applications [14] we might also want to know whether a timed automaton satisfies a A short version [18] of this paper appears in the Proceedings of the 13th ....

R. Alur, T. Feder, and T. A. Henzinger, "The benefits of relaxing punctuality," J. ACM, 43 (1996) 116-146

....number of clocks. Enabling conditions in a timed automaton are in the form of (clock) regions: a clock or the difference of two clocks is tested against an integer constant, e.g. x y 8. The region technique [2] has been used to analyze region reachability, to develop a number of temporal logics [1, 3 5, 20, 24, 26, 29] and for model checking tools [19, 23, 30] The region technique is useful, but obviously not enough. For instance, it is not possible, using the region technique, to verify whether clock values satisfying a non region property x 1 x 2 x 3 x 4 are reachable for a timed automaton. The ....

R. Alur, T. Feder, and T. A. Henzinger, "The benefits of relaxing punctuality," J. ACM, 43 (1996) 116-146

....three balls in room A, all of which should be moved to room B. Given the control knowledge that will be presented in Section 3.5, TALplanner will produce the following sequential plan: 12 J. Kvarnstrom and P. Doherty TALplanner #occ [0,1] pick(ball1, left) #occ [1,2] pick(ball2, right) #occ [2,3] move to(roomB) #occ [3,4] drop(ball1, left) #occ [4,5] drop(ball2, right) #occ [5,6] move to(roomA) #occ [6,7] pick(ball3, left) #occ [7,8] move to(roomB) #occ [8,9] drop(ball3, left) 3.2. Searching for Plans Although Figure 2 provides an abstract view of a planner for the TAL formalism, ....

....of which should be moved to room B. Given the control knowledge that will be presented in Section 3.5, TALplanner will produce the following sequential plan: 12 J. Kvarnstrom and P. Doherty TALplanner #occ [0,1] pick(ball1, left) #occ [1,2] pick(ball2, right) #occ [2,3] move to(roomB) #occ [3,4] drop(ball1, left) #occ [4,5] drop(ball2, right) #occ [5,6] move to(roomA) #occ [6,7] pick(ball3, left) #occ [7,8] move to(roomB) #occ [8,9] drop(ball3, left) 3.2. Searching for Plans Although Figure 2 provides an abstract view of a planner for the TAL formalism, it provides no information ....

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R. Alur, T. Feder, and T. A. Henzinger, `The benefits of relaxing punctuality', in Proceedings of the Tenth ACM Symposium on Principles of Distributed Computing (PODC'91), pp. 139--152, Montr'eal, Canada, (August 1991). Available at http://www.cis.upenn.edu/ alur/Podc91.ps.gz.

.... with model checking algorithms for automatic verification [Pnu77, QS82, CES83, EL86, VW86] This framework has been extended to the case of real time systems by adapting the existing specification formalisms and verification techniques in order to take into account hard timing constraints [AH89, ACD90, AFH91, HNSY92]. Timed automata and timed temporal logics have been defined by adding the ability of reseting and testing clocks, which allows to express upper and lower bounds on the time distances between events. For instance, this extension allows to express in the logic TPTL (timed PTL) AH89] properties ....

....their universality problem is undecidable [AD94] and hence, verifying a property expressed by timed automata is in general undecidable. Nevertheless, model checking algorithms have been proposed for timed logics like the branchingtime logic TCTL [ACD90, HNSY92] and the linear time logic MITL [AFH91]. However, in many practical cases we have considered, specifications are either not expressible in these logics or expressible in a cumbersome and not natural way. It is indeed possible the make the following observations. First, as it is well known, many properties are more simply expressed ....

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R. Alur, T. Feder, and T. Henzinger. The Benefits of Relaxing Punctuality. In PODC'91, 1991.

....circuits, communication protocols, and distributed programs. Recently, the interest in automated verification is moving towards concurrent real time systems. The properties to be verified are expressed in either a standard temporal logic like LTL and CTL # , or in its timed version like MITL [AFH96] and TCTL [ACD93] The practical applicability of model checking is strongly restricted by the state explosion problem, which is mainly caused by representing concurrency of operations by their interleaving. The paper deals with the automata theoretic approach [BVW94, SP00] to model checking of ....

....LTL# is an extension of LTL X, where the formulas of the form x y # n are also allowed. For example, G(p # (trueUntil (x y # 5) # q) is an LTL# formula. The logic MITL (Metric Interval Temporal Logic) is an extension of LTL X by subscribing the modality Until with time intervals I [AFH96]. For example, G(p # (trueUntil [3,5] q) is a MITL formula. The logic TCTL is an extension of CTL X by subscribing the modalities with expressions # n [ACD93] For example, AG(p # A(trueUntil #5 q) is a TCTL formula. Semantics. Let Paths(S) be a set of paths through S, i.e. maps # : R ....

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R. Alur, T. Feder, and T. Henzinger, The benefits of relaxing punctuality, Journal of ACM 43(1) (1996), 116--146.

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R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116--146, 1996.

No context found.

R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. In Proceedings of the Tenth Annual Symposium on Principles of Distributed Computing, pages 139--152. ACM Press, 1991.

No context found.

R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116--146, 1996.

No context found.

R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116--146, 1996.

....of positive real numbers. Temporal logics, which consider explicitly time, constitute a new research area of increasing interest. For temporal logics based on either discrete time or fictitious clock models see [AH94, EMSS90, JM86, Koy90, Ost90, PH88] The dense time model has been considered in [ACD93, AFH96, AH91, AH93, LN98, LN, PH88]. A well known timed temporal logic that uses a dense time model is TCTL (see [ACD93] Model checking is decidable in TCTL, but the satisfiability problem is undecidable. A branching real time temporal logic with a decidable satisfiability problem is STCT [LN98, LN] It differs from TCTL ....

....A branching real time temporal logic with a decidable satisfiability problem is STCT [LN98, LN] It differs from TCTL essentially in a simpler structure by means of which the semantics is defined and in the lack of the equality in the timing constraints. A decidable linear real time logic is MITL [AFH96]. An MIT structure is obtained by coupling a sequence of contiguous intervals with a sequence of states. In the MITL formulae the timing constraints are nonsingular intervals with rational end points. The restriction to nonsingular intervals coincides with the exclusion of equality in timing ....

[Article contains additional citation context not shown here]

R. Alur, T. Feder, and T.A. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116-146, 1996.

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R. Alur, T. Feder, and T. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116 -- 146, 1996.

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R. Alur, T. Feder, and T. A. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43:116--146, 1996.

No context found.

R. Alur, T. Feder, and T. A. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43(1):116--146, 1996.

No context found.

R. Alur, T. Feder, and T.A. Henzinger. The Benefits of Relaxing Punctuality. Journal of the ACM, 43:116--146, 1996.

No context found.

R. Alur, T. Feder, and T. Henzinger. The benefits of relaxing punctuality. Journal of the ACM, 43:116--146, 1996.

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R. Alur, T. Feder, T.A. Henzinger. The Benefits of Relaxing Punctuality. Journal of the ACM 43 (1996) 116-146.

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Rajeev Alur, Tomas Feder, and Thomas Henzinger. The benefits of relaxing punctuality. In Proceedings of the Thenth Annual ACM Symposium on Princeples of Distributed Computing (PODC'91), pages 139-- 152, 1991.

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R. Alur, T. Feder, and T. Henzinger. The Benefits of Relaxing Punctuality. In PODC'91, 1991.

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