81 research outputs found

    Grafting Hypersequents onto Nested Sequents

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    We introduce a new Gentzen-style framework of grafted hypersequents that combines the formalism of nested sequents with that of hypersequents. To illustrate the potential of the framework, we present novel calculi for the modal logics K5\mathsf{K5} and KD5\mathsf{KD5}, as well as for extensions of the modal logics K\mathsf{K} and KD\mathsf{KD} with the axiom for shift reflexivity. The latter of these extensions is also known as SDL+\mathsf{SDL}^+ in the context of deontic logic. All our calculi enjoy syntactic cut elimination and can be used in backwards proof search procedures of optimal complexity. The tableaufication of the calculi for K5\mathsf{K5} and KD5\mathsf{KD5} yields simplified prefixed tableau calculi for these logic reminiscent of the simplified tableau system for S5\mathsf{S5}, which might be of independent interest

    The Basic Principles of Uncertain Information Fusion. An organized review of merging rules in different representation frameworks

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    We propose and advocate basic principles for the fusion of incomplete or uncertain information items, that should apply regardless of the formalism adopted for representing pieces of information coming from several sources. This formalism can be based on sets, logic, partial orders, possibility theory, belief functions or imprecise probabilities. We propose a general notion of information item representing incomplete or uncertain information about the values of an entity of interest. It is supposed to rank such values in terms of relative plausibility, and explicitly point out impossible values. Basic issues affecting the results of the fusion process, such as relative information content and consistency of information items, as well as their mutual consistency, are discussed. For each representation setting, we present fusion rules that obey our principles, and compare them to postulates specific to the representation proposed in the past. In the crudest (Boolean) representation setting (using a set of possible values), we show that the understanding of the set in terms of most plausible values, or in terms of non-impossible ones matters for choosing a relevant fusion rule. Especially, in the latter case our principles justify the method of maximal consistent subsets, while the former is related to the fusion of logical bases. Then we consider several formal settings for incomplete or uncertain information items, where our postulates are instantiated: plausibility orderings, qualitative and quantitative possibility distributions, belief functions and convex sets of probabilities. The aim of this paper is to provide a unified picture of fusion rules across various uncertainty representation settings

    Bounded-analytic sequent calculi and embeddings for hypersequent logics

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    A sequent calculus with the subformula property has long been recognised as a highly favourable starting point for the proof theoretic investigation of a logic. However, most logics of interest cannot be presented using a sequent calculus with the subformula property. In response, many formalisms more intricate than the sequent calculus have been formulated. In this work we identify an alternative: retain the sequent calculus but generalise the subformula property to permit specific axiom substitutions and their subformulas. Our investigation leads to a classification of generalised subformula properties and is applied to infinitely many substructural, intermediate, and modal logics (specifically: those with a cut-free hypersequent calculus). We also develop a complementary perspective on the generalised subformula properties in terms of logical embeddings. This yields new complexity upper bounds for contractive-mingle substructural logics and situates isolated results on the so-called simple substitution property within a general theory

    Mathematics in Software Reliability and Quality Assurance

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    This monograph concerns the mathematical aspects of software reliability and quality assurance and consists of 11 technical papers in this emerging area. Included are the latest research results related to formal methods and design, automatic software testing, software verification and validation, coalgebra theory, automata theory, hybrid system and software reliability modeling and assessment

    Constructive Fuzzy Logics

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    We generalise Kripke’s semantics for Intuitionistic logic to Hajek’s BL and consider the constructive subsystems of GBLewf and Intuitionistic Affine logic or ALi. The genesis of our semantics is the Poset Product construction for GBL-algebras elucidated in a series of papers by Peter Jipsen, Simone Bova, and Franco Montagna. We present natural deduction systems for all of these systems and corresponding deduction theorems for these same. We present the algebraic semantics for each of the logics under consideration, demonstrate their soundness and completeness with respect to these algebraic semantics. We also show how the classical Kripke semantics for Intuitionistic logic can be recast in terms of Poset Products. We then proceed to the main results, showing how a very natural generalisation of the Kripke semantics holds for each of GBLewf , ALi and Hajek’s BL based on the embedding results of Jipsen and Montagna and the decidability results of Bova and Montagna. We demonstrate soundness and completeness of the logics under our semantics in each case, with the exception of ALi, whose robust completeness with respect to the intended models (relational models with frames valued in involutive pocrims) we leave as an open problem for the ambitious reader

    Représentation et combinaison d'informations incertaines : nouveaux résultats avec applications aux études de sûreté nucléaires

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    It often happens that the value of some parameters or variables of a system are imperfectly known, either because of the variability of the modelled phenomena, or because the availableinformation is imprecise or incomplete. Classical probability theory is usually used to treat these uncertainties. However, recent years have witnessed the appearance of arguments pointing to the conclusion that classical probabilities are inadequate to handle imprecise or incomplete information. Other frameworks have thus been proposed to address this problem: the three main are probability sets, random sets and possibility theory. There are many open questions concerning uncertainty treatment within these frameworks. More precisely, it is necessary to build bridges between these three frameworks to advance toward a unified handlingof uncertainty. Also, there is a need of practical methods to treat information, as using these framerowks can be computationally costly. In this work, we propose some answers to these two needs for a set of commonly encountered problems. In particular, we focus on the problems of:- Uncertainty representation- Fusion and evluation of multiple source information- Independence modellingThe aim being to give tools (both of theoretical and practical nature) to treat uncertainty. Some tools are then applied to some problems related to nuclear safety issues.Souvent, les valeurs de certains paramètres ou variables d'un système ne sont connues que de façon imparfaite, soit du fait de la variabilité des phénomènes physiques que l'on cherche à représenter,soit parce que l'information dont on dispose est imprécise, incomplète ou pas complètement fiable.Usuellement, cette incertitude est traitée par la théorie classique des probabilités. Cependant, ces dernières années ont vu apparaître des arguments indiquant que les probabilités classiques sont inadéquates lorsqu'il faut représenter l'imprécision présente dans l'information. Des cadres complémentaires aux probabilités classiques ont donc été proposés pour remédier à ce problème : il s'agit, principalement, des ensembles de probabilités, des ensembles aléatoires et des possibilités. Beaucoup de questions concernant le traitement des incertitudes dans ces trois cadres restent ouvertes. En particulier, il est nécessaire d'unifier ces approches et de comprendre les liens existants entre elles, et de proposer des méthodes de traitement permettant d'utiliser ces approches parfois cher en temps de calcul. Dans ce travail, nous nous proposons d'apporter des réponses à ces deux besoins pour une série de problème de traitement de l'incertain rencontré en analyse de sûreté. En particulier, nous nous concentrons sur les problèmes suivants :- Représentation des incertitudes- Fusion/évaluation de données venant de sources multiples- Modélisation de l'indépendanceL'objectif étant de fournir des outils, à la fois théoriques et pratiques, de traitement d'incertitude. Certains de ces outils sont ensuite appliqués à des problèmes rencontrés en sûreté nucléaire

    Coherence and audience reception in subtitling : with special reference to connectives

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    Due to time and space constraints, subtitling is often subject to reduction, which in turn may lead to information loss and hamper comprehension of subtitles. However, little research has been done to investigate the potential conflict between subtitle reduction and comprehension. Therefore, with the aim of exploring both ‘cohesion in text’ and ‘coherence in mind’, a two-phase study was designed to investigate textual reduction and audience reception with particular reference to connectives (e.g. moreover, but, because, and at first). More specifically, the present study aims to find to out how connectives are translated in different genres of factual TV programmes and whether and to what extent their reduction may affect audience comprehension. The first part of this study involved textual analysis of source texts and target texts of two TV genres: scripted documentaries and ‘spontaneous’ (i.e. unscripted) travel programmes. The occurrences of connectives in STs and TTs were manually counted and statistically analysed. The results showed that the addition or omission of connectives was related to the difference between these two genres: documentaries were translated more explicitly with more connectives translated and added, while a travel programme were translated more implicitly with more connectives omitted. The second part of this study involved a questionnaire survey using four English clips (two scripted documentaries and two spontaneous travel programmes from Discovery Channel) to test the perception of 158 participants on the reduction of connectives in Chinese subtitles. The results of the survey showed the participants seemed to have no difficulty comprehending Chinese subtitles when most English connectives were intentionally not translated. That is, the omission of connectives did not seem to affect their perception on the coherence of subtitles, which may be explained by contextual factors such as register (field, tenor, and mode), pragmatic principles (e.g. the cooperative principle and Gricean maxims), and multi-semiotic features of subtitling (e.g. co-presence of subtitles, image, and sound). In other words, the present study shows that reduction in subtitling could be justified from the perspective of context in subtitling. These findings can be further applied to the teaching and assessment of subtitling.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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