[pt] A aplicação de linguagens declarativas baseadas na programação em lógica tem sido bastante difundida devido ao grande interesse hoje existente na área de Inteligência Artificial. Porém, o uso destas linguagens ainda não é muito evidente devido à restrições de desempenho, portabilidade, capacidade de integração com outras linguagens, etc. O presente trabalho contém a definição e implementação de uma extensão de programação em lógica para o C, denominada CLog, que têm como objetivo suprir as deficiências acima, permitindo, principalmente, a implementação de aplicações que apresentem características de programação em lógica integrada à programação imperativa em um mesmo ambiente de desenvolvimento. / [en] The use of declarative languages based in logic programming has been spread out due to the great interest in Artificial Intelligence. However, the use of these languages is not evident yet due to performance, portability, integration to other languages capability and other restrictions. This work contains the definition and implementation of a logic programming extension for C called Clog, which intends to cover the above deficiencies, allowing, mainly, the implementation of applications that have logic programming characteristics integrated to interative programming in the same development environment.

[pt] Haeusler e Pequeno desenvolveram um método de prova de teoremas baseado em jogos semânticos introduzidos por Hintikka. Posteriormente Rios desenvolveu o programa PROGRAME que implementa este método. Este trabalho descreve um ambiente de programação lógica desenvolvido com a finalidade de oferecer ao usuário facilidades de programação lógica suportada pelo provador PROGRAME. O ambiente foi idealizado o mais próximo possível nos ambientes PROLOG, com a facilidade adicional de permitir que no código do programa a ele submetido sejam utilizados indiferentemente goals a serem provados neste ambiente ou PROGRAME. / [en] Haeusler and Pequeno developed a theorem proving method based on semântica games introduced by Hintikka. Later, Rios developed the program PROGRAME witch implements this method. Our work describes a logic programming environment developed with the aim of offering the user logic programming facilities supported by the PROGRAME prover. The programming environment was chosen to be PROLOG-like with additional facility of permiting that a given goal can b proved both by or environment and by the PROGRAME prover

[pt] A gerência de redes telefônicas nas modernas concessionáras do chamado Primeiro Mundo têm se apoiado, cada vez mais, sobre sistemas baseados em conhecimento. Esses sistemas inteligentes são apresentados como solução capaz de fazer face às exigências de qualidade e confiabilidade feitas pelos usuários ligados a redes, as quais crescem em dimensão e complexidade, num ritmo jamais visto. Este trabalho incursiona nesse campo e apresenta o projeto, seu desenvolvimento e a implementação, baseada na Programação em Lógica, de um sistema para auxílio à emissão de telecomandos sobre a Rede Nacional de Telefonia, operada pela EMBRATEL. Adicionalmente, apresentamos um levantamento das principais técnicas de obtenção e representação de conhecimento para fins de utilização em computadores eletrônicos. / [en] The management of telephone networks in developed countries hás been based, in a ever-growing scale, on knowledge-based systems. Those intelligent systems have been presented as a means to face the demands in quality and reliability posed by users of those networks, which have been expanding at an uncredibly fast pace. This paper tries to explore this area and presents the project, its development and implement based on Logic Programming, of a system for aiding the sending commands upon the National Telephone Network, operated by EMBRATEL. Additionally we have done a survey of the main techniques for the acquisition and representation of knowledge related to electronic computing

[pt] A primeira parte deste trabalho consiste num estudo das desigualdades lineares que aparecem na síntese de funções lógicas por single-threshold. São desenvolvidas condições necessárias e suficientes para existência de solução, e também estabelecidas condições para a redução das desigualdades. Na segunda parte é proposto um método para calcular uma solução ótima para o sistema, sob certas condições de projeto. Finalmentesão apresentados métodos para realiza, com multithreshold devices, funções lógicas não realizáveis por single-threshold devices. / [en] The first part of this thesis is a theoretical study of sets of inequalities that appear in the synthesis of logical sufficient conditions are developd for existence of solution of the inequalities. In the second part, a numerical method for calculating proposed. Following this development, logical functions that cannot be realized by a single-threshold device are studied. Using the conditions developed before for single- threshold, methods are presented for realization of these functions by multithreshold devices.

This thesis is concerned with the study of nonstandard models in measure theory and in functional analysis. In measure theory, we define elementary numerosities, that are additive measures that take on values in a non-archimedean field and for which the measure of every singleton is 1. We have shown that, by taking the ratio with a suitable unit of measurement, from a numerosity it can be defined a non-atomic real-valued measure, and that every non-atomic measure can be obtained from a numerosity by this procedure. We then used numerosities to develop a model for the probability of infinite sequences of coin tosses coherent with the original ideas of Laplace. In functional analysis, we introduce a space of functions of nonstandard analysis with a formally finite domain, that extends both the space of distributions and the space of Young measures. Among the applications of this space of functions, we develop a continuous-in-time, discrete-in-space nonstandard formulation for a class of ill-posed forward-backward parabolic equations, and on the study of the regularity and asymptotic behaviour of its nonstandard solutions. This approach proved to be a viable alternative to the study of the vanishing viscosity limit of the solution of a pseudoparabolic regularization of the original problem.

Il lavoro di ricerca si dedica all’analisi critica di alcuni illustri esponenti delle logiche del dialogo, ossia un ampio novero di teorie che hanno inteso ricercare all’interno della relazione dialogica criteri di validità per il ragionamento e per l’argomentazione. A fini introduttivi, nel primo capitolo ci si è occupati della svolta rappresentata dalla filosofia dialogica di inizio Novecento, grazie ai cui principali esponenti – tra gli altri, Martin Buber, Franz Rosenzweig e Ferdinand Ebner – ha preso vita un movimento di reazione alle prospettive individualistiche tipiche dell’antropologia moderna. Nel secondo capitolo, di nodale importanza per la struttura generale del lavoro, si è riflettuto, attraverso il confronto con Platone ed Aristotele, sulle radici logico-filosofiche dei concetti di “dialogo” e “dialettica”, troppo spesso utilizzati in maniera sinonimica. È emerso che, mentre nella concezione platonica – almeno nei limiti entro i quali ce ne si è occupati – dialettica e dialogo (reale) potrebbero non darsi assieme, la dialettica aristotelica avrebbe il merito di recuperare il carattere eminentemente dialogico del procedimento elenctico inaugurato da Socrate. Nella seconda parte della ricerca si è così passati all’analisi critica di alcuni illustri rappresentati delle logiche del dialogo del Novecento, che rinvengono proprio in Aristotele un punto di riferimento comune. Sono stati presi in esame i tratti essenziali di due espressioni formali delle logiche del dialogo: la Dialogische Logik di Paul Lorenzen e la Game-Theoretical-Semantic di Jaakko Hintikka. Oltre alle peculiarità di ciascuna teoria, si è messo in luce come queste condividano l’obiettivo di ampliare la capacità espressiva della logica formale, avvicinandola attraverso l’elemento dialogico ai contesti di uso comune del linguaggio e dell’argomentazione. Il quarto capitolo, infine, è dedicato alle logiche del dialogo di natura non-formale, ossia gli approcci teorici che utilizzano la struttura del dialogo per rinvenire dei criteri di razionalità applicabili agli ordinari contesti argomentativi. Quest’ultima sezione della ricerca è scandita dalla lettura critica di tre testi. Il primo testo è Fallacies (1970) di Charles Hamblin, dall’esame del quale, oltre agli elementi seminali del successivo approccio di studi dell’Informal Logic, è emersa anche una lettura eminentemente retorica dell’argomentazione. Tra i concetti innovativi introdotti da Hamblin si annovera il “commitment dialogico” che, invero, rappresenta il fulcro del secondo testo esaminato: Commitment in Dialogue (1995) di Douglas Walton ed Erik Krabbe. La loro proposta, nonostante abbracci un marcato pluralismo logico, riesce, grazie proprio al “commitment dialogico”, ad evitare derive relativistiche e a far convivere tra loro i diversi approcci normativo e descrittivo. In ultima battuta, si è recuperato il testo The Dialogical Roots of Deduction (2021) di Catarina Dutilh Novaes, già incontrato durante la rilettura in termini dialogici della sillogistica aristotelica, per mettere in evidenza come l’Autrice giustifichi l’interpretazione dialogica del ragionamento deduttivo anche dalle diverse prospettive storica e cognitiva, suggerendo così la convergenza di più ambiti del sapere verso una concezione eminentemente relazionale dell’uomo che, come specificato nelle nostre conclusioni, potrà avere ripercussioni anche in ambito filosofico-giuridico.

In this thesis, we study the problem of reasoning and query answering over contextualized knowledge in quad format augmented with expressive forall-existential bridge rules. Such bridge rules contain conjunctions, existentially quantified variables in the head, and are strictly more expressive than the bridge rules considered so far in similar setting. A set of quads together with forall-existential bridge rules is called a quad-system. We show that query answering over quad-systems in their unrestricted form is undecidable, in general. We propose various subclasses of quad-systems, for which query answering is decidable. Context-acyclic quad-systems do not allow the context dependency graph of the bridge rules to have cycles passing through triple-generating (value-generating) contexts, and hence guarantees the chase (deductive closure) to be finite. Csafe, msafe and safe classes of quad-systems restricts the structure of descendance graph of Skolem blank nodes generated during chase process to be directed acyclic graphs (DAGs) of bounded depth, and hence has finite chases. RR and restricted RR quad-systems do not allow for the creation of Skolem blank nodes, and hence restrict the chase to be of polynomial size. Besides the undecidability result of unrestricted quad-systems, tight complexity bounds has been established for each of the classes we have introduced. We then compare the problems, (resp. classes,) we address (resp. derive) in this thesis, for quad-systems with analogous problems (resp. classes) in the realm of forall-existential rules. We show that the query answering problem over quad-systems is polynomially equivalent to the query answering problem over ternary forall-existential rules, and the technique of safety, we propose, is strictly more expressive than existing well known techniques such joint acyclicity and model maithful acyclicity, used for decidability guarantees, in the realm of forall-existential rules.

Many projects have dealt with mappings between classifications both in computer science and digital library communities. The adopted solutions range from fully manual to fully automatic approaches. Manual approaches are very precise, but automation becomes unavoidable when classifications contain thousands of nodes with millions of candidate correspondences. As fun-damental preliminary step towards automation, S-Match converts classifications into formal on-tologies, i.e. lightweight ontologies. Despite many solutions to the problem have been offered, with S-Match representing a state of the art matcher with good accuracy and run-time perfor-mance, there are still several open problems. In particular, the problems addressed in this thesis include: (a) Run-time performance. Due to the high number of calls to the SAT reasoning engine, semantic matching may require exponential time; (b) Maintenance. Current matching tools offer poor support to users for the process of creation, validation and maintenance of the correspond-ences; (c) Lack of background knowledge. The lack of domain specific background knowledge is one important cause of low recall. As significant progress to (a) and (b), we describe MinSMatch, a semantic matching tool we developed evolving S-Match that computes the minimal mapping between two lightweight ontologies. The minimal mapping is that minimal subset of correspondences such that all the others can be efficiently computed from them and are therefore said to be redundant. We provide a formal definition of minimal and, dually, redundant map-pings, evidence of the fact that the minimal mapping always exists and it is unique and a correct and complete algorithm for computing it. Our experiments demonstrate a substantial improve-ment in run-time. Based on this, we also developed a method to support users in the validation task that allows saving up to 99% of the time. We address problem (c) by creating and by making use of an extensible diversity-aware knowledge base providing a continuously growing quantity of properly organized knowledge. Our approach is centered on the fundamental notions of domain and context. Domains, developed by adapting the faceted approach from library science, are the main means by which diversity is captured and allow scaling as with them it is possible to add new knowledge as needed. Context allows a better disambiguation of the terms used and re-ducing the complexity of reasoning at run-time. As proof of the applicability of the approach, we developed the Space domain and applied it in the Semantic Geo-Catalogue (SGC) project.

Description Logics (DLs) are a family of logic-based knowledge representation formalisms aimed at representing the knowledge of an application domain in a structured way one of whose main characteristic is the emphasis on reasoning. Since the last two decades Description logics have been widely studied and applied to numerous areas of computer science (including artificial intelligence, formal verification, database theory, natural language processing and distributed computing). In recent years, however, the interest in the problem of automated reasoning in Description Logics has seen a tremendous growth because of the explosion of new notable applications in the domains of Semantic Web and of bio-medical ontologies. The more real-world problems are represented through DL-based ontologies the more these new applications represents a challenge due to the required efficiency in handling complex logical constructors (e.g. numerical constraints) and in handling the huge dimensions of this kind of ontologies. For these reasons the development of efficient algorithms and procedures for reasoning in Description Logic has become crucial. SAT-based technologies, in the meanwhile, proved to be mature and largely successful in many other automated reasoning fields, first of all on many very hard practical applications of formal verification, often huge characterized by problems of huge dimension. In the last twenty years, in fact, we have witnessed an impressive advance in the efficiency of SAT techniques, which has brought problems of hundreds of millions of clauses and variables to be at the reach of the freely-available state-of-the-art solvers. As a consequence, many problems have been successfully solved by mean of SAT-based techniques and these approaches are currently state-of-the-art in the respective communities (among all Model Checking). Furthermore, the progress in SAT-solving techniques, together with the concrete needs from real applications, have inspired significant research on richer and more expressive Boolean formalism, like Satisfiability Modulo Theories (SMT), and on the use of the SAT formalism to solve problems with a wider extent (e.g. to compute interpolants, unsatisfiable cores, all-SAT). The research trends in Description Logic, its manifold practical applications, the quest of efficient and scalable procedures, on one hand, the wide variety of mature and efficient techniques offered by the SAT research area, on the other hand, motivated our research. In this thesis dissertation we explore the idea of exploiting the power and efficiency of state-of-the-art SAT-based techniques for automated reasoning and ontology manipulation in Description Logics, proposing a convenient alternative to the traditional tableau based algorithms. With this aim we propose and develop novel and complete approaches able to solve Description Logic problems as SAT and SMT ones, by mean of sound and complete encodings. On these encodings we develop new procedures and optimizations techniques based on a variety of existing SAT-based formalisms and technologies. In this work, in particular, we focus on three gradually harder reasoning problems in Description Logics which tackle increasingly more expressive languages or increasingly harder reasoning services, among which we face also non-standard services supporting the debugging of ontologies like modularization and axiom pinpointing. We implemented our approaches in tools which integrate with the available SAT/SMT-solvers; finally, we show the effectiveness of our novel approaches through very extensive empirical evaluations on benchmarks and ontologies from real application, in which we compare our performance against the other state-of-the-art available systems. Notice that any advance in the exploited Boolean reasoning techniques/tools will be freely inherited from our proposed approaches extending also to Description Logics/ontologies the benefits of the observable great and fast advance in the efficiency of SAT-based techniques.

Assuring safety and reliability is fundamental when developing a safety critical system. Road, naval and avionic transportation; water and gas distribution; nuclear, eolic, and photovoltaic energy production are only some examples where it is mandatory to guarantee those properties. The continuous increasing in the design complexity of safety critical system calls for a never ending sought of new and more advanced analytical techniques. In fact, they are required to assure that undesired consequences are highly improbable. In this Thesis we introduce a novel methodology able to raise the bar in the area of automated safety and reliability analysis. The proposed approach integrates a series of techniques, based on symbolic model checking, into the current development process of safety critical systems. Moreover, our methodology and the resulting techniques are thereafter applied to a series of real-world case studies, developed in collaboration with authoritative entities such as NASA and the Boeing Company.