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On the Satisfiability of Temporal Logics with Concrete DomainsCarapelle, Claudia 08 December 2015 (has links) (PDF)
Temporal logics are a very popular family of logical languages, used to specify properties of abstracted systems. In the last few years, many extensions of temporal logics have been proposed, in order to address the need to express more than just abstract properties.
In our work we study temporal logics extended by local constraints, which allow to express quantitative properties on data values from an arbitrary relational structure called the concrete domain.
An example of concrete domain can be (Z, <, =), where the integers are considered as a relational structure over the binary order relation and the equality relation.
Formulas of temporal logics with constraints are evaluated on data-words or data-trees, in which each node or position is labeled by a vector of data from the concrete domain. We call the constraints local because they can only compare values at a fixed distance inside such models.
Several positive results regarding the satisfiability of LTL (linear temporal logic) with constraints over the integers have been established in the past years, while the corresponding results for branching time logics were only partial.
In this work we prove that satisfiability of CTL* (computation tree logic) with
constraints over the integers is decidable and also lift this result to ECTL*, a proper extension of CTL*.
We also consider other classes of concrete domains, particularly ones that are \"tree-like\". We consider semi-linear orders, ordinal trees and trees of a fixed height, and prove decidability in this framework as well. At the same time we prove that our method cannot be applied in the case of the infinite binary tree or the infinitely branching infinite tree.
We also look into extending the expressiveness of our logic adding non-local constraints, and find that this leads to undecidability of the satisfiability problem, even on very simple domains like (Z, <, =). We then find a way to restrict the power of the non-local constraints to regain decidability.
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On the Satisfiability of Temporal Logics with Concrete DomainsCarapelle, Claudia 04 November 2015 (has links)
Temporal logics are a very popular family of logical languages, used to specify properties of abstracted systems. In the last few years, many extensions of temporal logics have been proposed, in order to address the need to express more than just abstract properties.
In our work we study temporal logics extended by local constraints, which allow to express quantitative properties on data values from an arbitrary relational structure called the concrete domain.
An example of concrete domain can be (Z, <, =), where the integers are considered as a relational structure over the binary order relation and the equality relation.
Formulas of temporal logics with constraints are evaluated on data-words or data-trees, in which each node or position is labeled by a vector of data from the concrete domain. We call the constraints local because they can only compare values at a fixed distance inside such models.
Several positive results regarding the satisfiability of LTL (linear temporal logic) with constraints over the integers have been established in the past years, while the corresponding results for branching time logics were only partial.
In this work we prove that satisfiability of CTL* (computation tree logic) with
constraints over the integers is decidable and also lift this result to ECTL*, a proper extension of CTL*.
We also consider other classes of concrete domains, particularly ones that are \"tree-like\". We consider semi-linear orders, ordinal trees and trees of a fixed height, and prove decidability in this framework as well. At the same time we prove that our method cannot be applied in the case of the infinite binary tree or the infinitely branching infinite tree.
We also look into extending the expressiveness of our logic adding non-local constraints, and find that this leads to undecidability of the satisfiability problem, even on very simple domains like (Z, <, =). We then find a way to restrict the power of the non-local constraints to regain decidability.
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Définissabilité et synthèse de transductions / Definability and synthesis of transductionsLhote, Nathan 12 October 2018 (has links)
Dans la première partie de ce manuscrit nous étudions les fonctions rationnelles, c'est-à-dire définies par des transducteurs unidirectionnels. Notre objectif est d'étendre aux transductions les nombreuses correspondances logique-algèbre qui ont été établies concernant les langages, notamment le célèbre théorème de Schützenberger-McNaughton-Papert. Dans le cadre des fonctions rationnelles sur les mots finis, nous obtenons une caractérisation à la Myhill-Nerode en termes de congruences d'indice fini. Cette caractérisation nous permet d'obtenir un résultat de transfert, à partir d'équivalences logique-algèbre pour les langages vers des équivalences pour les transductions. En particulier nous montrons comment décider si une fonction rationnelle est définissable en logique du premier ordre. Sur les mots infinis, nous pouvons également décider la définissabilité en logique du premier ordre, mais avec des résultats moins généraux.Dans la seconde partie nous introduisons une logique pour les transductions et nous résolvons le problème de synthèse régulière : étant donnée une formule de la logique, peut-on obtenir un transducteur bidirectionnel déterministe satisfaisant la formule ? Les fonctions réalisées par des transducteurs bidirectionnels déterministes sont caractérisés par plusieurs modèles différents, y compris par les transducteurs MSO, et ont ainsi été nommées transductions régulières. Plus précisément nous fournissons un algorithme qui produit toujours une fonction régulière satisfaisant une spécification donnée en entrée.Nous exposons également un lien intéressant entre les transductions et les mots avec données. Par conséquent nous obtenons une logique expressive pour les mots avec données, pour laquelle le problème de satisfiabilité est décidable. / In the first part of this manuscript we focus on the study of rational functions, functions defined by one-way transducers.Our goal is to extend to transductions the many logic-algebra correspondences that have been established for languages, such as the celebrated Schützenberger-McNaughton-Papert Theorem. In the case of rational functions over finite words, we obtain a Myhill-Nerode-like characterization in terms of congruences of finite index. This characterization allows us to obtain a transfer result from logic-algebra equivalences for languages to logic-algebra equivalences for transductions. In particular, we show that one can decide if a rational function can be defined in first-order logic.Over infinite words, we obtain weaker results but are still able to decide first-order definability.In the second part we introduce a logic for transductions and solve the regular synthesis problem: given a formula in the logic, can we obtain a two-way deterministic transducer satisfying the formula?More precisely, we give an algorithm that always produces a regular function satisfying a given specification.We also exhibit an interesting link between transductions and words with ordered data. Thus we obtain as a side result an expressive logic for data words with decidable satisfiability.
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Automatic Synthesis of Systems with Data: Synthèse Automatique de Systèmes avec DonnéesExibard, Leo 20 September 2021 (has links) (PDF)
A reactive system is a system that continuously interacts with its environment. The environment provides an input signal, to which the system reacts with an output signal, and so on ad infinitum. In reactive synthesis, the goal is to automatically generate an implementation from a specification of the reactive and non-terminating input/output behaviours of a system. In the classical setting, the set of signals is assumed to be finite. however, this assumption is not realistic to model systems which process sequences of signals accompanied with data from a possibly infinite set (e.g. a client id, a sensor value, etc.), which need to be stored in memory and compared against each other.The goal of this thesis is to lift the theory of reactive system synthesis over words on a finite alphabet to data words. The data domain consists in an infinite set whose structure is given by predicates and constants enriched with labels from a finite alphabet. In this context, specifications and implementations are respectively given as automata and transducers extended with a finite set of registers that they use to store data values. To determine the transition to take, they compare the input data with the content of the registers using the predicates of the domain.In a first part, we consider both the bounded and unbounded synthesis problem; the former additionally asks for a bound on the number of registers of the implementation, along with the specification. We do so for different instances, depending on whether the specification is a nondeterministic, universal (a.k.a. co-non-deterministic) or deterministic automaton, for various domains.While the bounded synthesis problem is undecidable for non-deterministic specifications, we provide a generic approach consisting in a reduction to the finite alphabet case, that is done through automata-theoretic constructions. This allows to reprove decidability of bounded synthesis for universal specifications over (ℕ,=), and to obtain new ones, such as the case of a dense order, or the ability of data guessing, all with a 2-ExpTime complexity.We then move to the unbounded synthesis problem, which is undecidable for specifications given by non-deterministic and universal automata, but decidable and ExpTime-complete for deterministic ones over (ℕ,=) and (ℚ,<). We also exhibit a decidable subclass in the case of (ℕ,<), namely one-sided specifications.In a second part, we lift the reactivity assumption, considering the richer class of implementations that are allowed to wait for additional input before reacting, again over data words. Specifications are modelled as non-deterministic asynchronous transducers, that output a (possibly empty) word when they read an input data. Already in the finite alphabet case, their synthesis problem is undecidable.A way to circumvent the difficulty is to focus on functional specifications, for which any input sequence admits at most one acceptable output. Targeting programs computed by input-deterministic transducers is again undecidable, so we shift the focus to deciding whether a specification is computable, in the sense of the classical extension of Turing-computability to infinite inputs. We relate this notion with that of continuity for the Cantor distance, which yields a decidable characterisation of computability for functional specifications given by asynchronous register transducers over (ℕ,=) and for the superseding class of oligomorphic data domains, that also encompasses $(ℚ,<)$. The study concludes with the case of (ℕ,<), that is again decidable. Overall, we get PSpace-completeness for the problems of deciding computability and refined notions, as well as functionality. / Option Informatique du Doctorat en Sciences / info:eu-repo/semantics/nonPublished
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