Se intenta mostrar la génesis de la corriente denominada "Informal logic" y la conceptualizacién de dos temas instrumentales que se pueden enseñar desde esta perspectiva: las clases de argumentación según su estructura y la técnica de diagramación de Monroe Beardsley.

La lógica de la conciencia es una extensión de la lógica epistémica que solventa el problema de la omnisciencia lógica incorporando un operador de conciencia para separar el conocimiento explícito del implícito. Este informe recopila los principales textos tanto de los orígenes de esta lógica, así como de sus desarrollos en las últimas tres décadas. En concreto analiza los enfoques desde la lógica epistémica dinámica, desde su combinación con otras lógicas y los enfoques de teoría (...) de juegos. (shrink)

EI objetivo de este artículo es presentar los principios de la programación lógica borrosa y de sus principales variantes, ilustrándolas a través de un conjunto de aproximaciones que, a nuestro entender, son representativas de los avances en esta área. También incluimos la descripción de otros sistemas de programación lógica que se sustentan en lógicas de la incertidumbre diferentes de la lógica borrosa. En esta presentación presuponemos que la mayoría de los lectores no son expertos en programación (...) class='Hi'>lógica; para seguirla sólo se requiere un conocimiento básico de la lógica de predicados.The purpose of this paper is to present the principles of the fuzzy logic programming, exemplifying them by a couple of proposals that we think are representatives of the advances in this field. We include also the description of another systems of logic programming with uncertain information that are based on other logics of uncertainty which are different from fuzzy logic. This article only presuppose anelementary knowledge of the classical first-order logic. (shrink)

Importantes pensadores de todos los tiempos coinciden en admitir como fundamenal recurso de la inteligencia una clase de inferencia lógica no exactamente del tipo de la lógica simbólica tradicional. En el siglo XX, período de florecimiento de esta lógica, lógicos como Bertrand Russell se refieren a una "inferencia no demostrativa" que interviene en la mayoría de las más importantes argumentaciones filosóficas y no filosóficas.

O método axiomático é considerado uma das principais ferramentas para a sistematização do conhecimento. Inaugurado na Grécia antiga, o método axiomático passou por grandes mudanças ao longo da história. Este artigo busca estabelecer as fases de evolução da abordagem axiomática. Divide-se a axiomática em três categorias: concreta, abstrata ou formal. Divide-se em a axiomática três categorias: concreta, abstrata ou formal. Em um segundo momento, o artigo aproxima a utilização do método axiomático na física quântica, através da apresentação informal da (...) axiomática de uma lógica não-reflexiva. Batizada pelo filósofo e lógico brasileiro Newton da Costa como Lógica de Schrödinger, sua motivação encontra-se na posição teórica perante o status ontológico das entidades postuladas pela física quântica, denominada Received View. (shrink)

Lógica viva de Vaz Ferreira (1910) es considerada una original contribución a la reflexión lógica ---por ejemplo, recientemente, Vega Reñón (2013 y 2019) ha resaltado su relevancia---. Lógica viva puede interpretarse como la fundamentación, exposición e implementación parcial de un programa de indagación lógica, que anima una relectura de los contenidos tradicionales y una ampliación del elenco tradicional de paralogismos (Seoane 2019b). Al hacerlo entrelaza invención lógica y pedagógica. Desde esta óptica, resulta clave el contraste (...) entre su estilo de ejemplificar y el estilo usual de los manuales de lógica. Este trabajo propone una interpretación de la política de ejemplificación de Lógica viva. (shrink)

The logical form of a discourse—such as a proposition, a set of propositions, an argument, or an argumentation—is obtained by abstracting from the subject-matter of its content terms or by regarding the content terms as mere place-holders or blanks in a form. In a logically perfect language the logical form of a proposition, a set of propositions, an argument, or an argumentation is determined by the grammatical form of the sentence, the set of sentences, the argument-text, or the argumentation-text expressing (...) it. Two such discourse-texts are said to have the same grammatical form, in this sense, if a uniform one-one substitution of content words transforms the one exactly into the other. The sentence ‘Abe properly respects every agent who respects himself’ may be regarded as having the same grammatical form as the sentence ‘Ben generously assists every patient who assists himself’. (shrink)

Desde su creación moderna a principios de la década de los 70, la lógica informal ha puesto un especial énfasis en el análisis de las falacias y los esquemas de diálogo argumentativo. Desarrollos simultáneos en los círculos que se ocupan de los actos de comunicación de habla exhiben una concentración en el carácter dialéctico de la discusión.

This anonymous source publication of a university discussion held in Prague about 1400 provides us with new information about medieval semantics after Peter of Spain and Richard Billingham. The edition is the basis of a partial reconstruction of Thomas of Cleves’ _Logica_.

EI objetivo de este artículo es presentar los principios de la programación lógica borrosa y de sus principales variantes, ilustrándolas a través de un conjunto de aproximaciones que, a nuestro entender, son representativas de los avances en esta área. También incluimos la descripción de otros sistemas de programación lógica que se sustentan en lógicas de la incertidumbre diferentes de la lógica borrosa. En esta presentación presuponemos que la mayoría de los lectores no son expertos en programación (...) class='Hi'>lógica; para seguirla sólo se requiere un conocimiento básico de la lógica de predicados.The purpose of this paper is to present the principles of the fuzzy logic programming, exemplifying them by a couple of proposals that we think are representatives of the advances in this field. We include also the description of another systems of logic programming with uncertain information that are based on other logics of uncertainty which are different from fuzzy logic. This article only presuppose anelementary knowledge of the classical first-order logic. (shrink)

A Lógica Contemporânea dá pouca ou, mesmo, nenhuma atenção à construção de argumentos para uma conclusão dada, diferentemente do que ocorre nos Analíticos Anteriores, de Aristóteles. O procedimento de Aristóteles foi, posteriormente, compilado sob a forma de um diagrama lógico conhecido como “Ponte de Asnos” (Pons Asinorum). Neste trabalho proponho um procedimento para a construção de argumentos para uma dada conclusão, no âmbito da Lógica Proposicional Clássica, abstraído do procedimento de Aristóteles. Utilizo a noção de informação semântica como (...) fio de Ariadne para a obtenção do procedimento. (shrink)

RESUMO O presente artigo apresenta uma semântica baseada nas atitudes cognitivas de aceitação e rejeição por uma sociedade de agentes para lógicas inspiradas no First Degree Entailment de Dunn e Belnap. Diferente das situações epistêmicas originalmente usadas em E, as atitudes cognitivas não coincidem com valores-de-verdade e parecem mais adequadas para as lógicas que pretendem considerar o conteúdo informacional de proposições “ditas verdadeiras” tanto quanto as proposições “ditas falsas” como determinantes da noção de validade das inferências. Após analisar algumas lógicas (...) associadas à semântica proposta, introduzimos a lógica E B cuja relação de consequência semântica subjacente - o B-entailment - é capaz de expressar diversos tipos de raciocínio em relação às atitudes cognitivas de aceitação e rejeição. Apresentamos também um cálculo de sequentes correto e completo para E B.ABSTRACT In the present work I introduce a semantics based on the cognitive attitudes of acceptation and rejection entertained by a given society of agents for logics inspired on Dunn and Belnap’s ‘First Degree Entailment’. Distinctly from the original epistemic situation of E, the cognitive attitudes do not coincide with truth-values and it seems more suitable for logics that intend to consider the informational content of propositions “said to be true” as well as propositions “said to be false” as determinants of the notion of logical validity. After analyzing some logics associated with the proposed semantics, we introduce the logic E B, whose underlying semantic entailment relation - the B-entailment - is able to express several kinds of reasoning towards the cognitive attitudes of acceptance and rejection. Acorrect and complete sequent calculus for E B is also presented. (shrink)

Sintetiza parte da pesquisa que a autora vem desenvolvendo sobre a possibilidade de ministrar conteúdos lógicos sob um viés essencialmente informal. Por conseguinte, procura fundamentar a importância da inclusão de conceitos de lógica no Ensino Médio.

Anthony Shiver (2013) desenvolveu dois jogos de cartas lógicas para a prática da derivação no contexto da Lógica Proposicional Clássica. Embora ele tenha apresentado os contornos gerais desses jogos, muitos detalhes do desenho deles estão faltando. Neste artigo proponho uma metodologia para o desenho detalhado do primeiro dos jogos de Shiver. Esta metodologia utiliza uma abordagem informacional para a seleção das cartas do baralho, que conforma-se a critérios de alcançabilidade de cada carta e de balanço entre elas.

The aim of this paper is to provide epistemic reasons for investigating the notions of informal rigour and informal provability. I argue that the standard view of mathematical proof and rigour yields an implausible account of mathematical knowledge, and falls short of explaining the success of mathematical practice. I conclude that careful consideration of mathematical practice urges us to pursue a theory of informal provability.

In order to present the incidence of the dynamic turn in the logic of scientific research, we begin with a section, in this article, that deals with logical games as triggers of this dynamic turn in contemporary logic, together with the program of logical dynamics of information and interaction. We briefly introduce the main characteristics of the logic favorable to independence and the game-theoretical semantics, of dialogical logic, as well as the essential elements of this program. Although from any of (...) these points of view we have a list of logical tools to deal with more clearly epistemological issues, we highlight the role of dynamic epistemic logic, to which we dedicate the following section. There follows another one in which we enter the logical studies of abduction as one of the fundamental problems of contemporary epistemology and, in a new section, in terms of the theoretical constructs of the preceding sections, we present and explain a phenomenon that emerged in the field of linguistics, the case of the discovery of the Amazonian language pirahã, which should be considered an anomaly within the framework of the Chomskian theory. (shrink)

Previous discussions of Robb’s work on space and time have offered a philosophical focus on causal interpretations of relativity theory or a historical focus on his use of non-Euclidean geometry, or else ignored altogether in discussions of relativity at Cambridge. In this paper I focus on how Robb’s work made contact with those same foundational developments in mathematics and with their applications. This contact with applications of new mathematical logic at Göttingen and Cambridge explains the transition from his electron research (...) to his treatment of relativity in 1911 and finally to the axiomatic presentation in 1914 in terms of postulates. At the heart of Robb’s physical optics was the model of the light cone. The model underwent a transition from a working mechanical model in the Maxwellian Cambridge sense of a pedagogical and research tool to the semantic model, in the logical, model-theoretic sense. Robb tracked this transition from the 19th- to the 20th-century conception with the earliest use of the term ‘model’ in the new sense. I place his cone models in a genealogy of similar models and use their evolution to track how Robb’s physical researches were informed by his interest in geometry, logic and the foundations of mathematics. (shrink)

. We explore a connection between different ways of representing information in computer science. We show that relational databases, modules, algebraic specifications and constraint systems all satisfy the same ten axioms. A commutative semigroup together with a lattice satisfying these axioms is then called an “information algebra”. We show that any compact consequence operator satisfying the interpolation and the deduction property induces an information algebra. Conversely, each finitary information algebra can be obtained from a consequence operator in this way. Finally (...) we show that arbitrary (not necessarily finitary) information algebras can be represented as some kind of abstract relational database called a tuple system. (shrink)

The book is an undergraduate-level introduction to first-order logic and proposi­tional modal logic. The book presents symbolic logic in a way that is pedagogi­cally attractive and formally rigorous. The main concepts are formally defined, in­formally explained, and illustrated with several examples. The book is aimed at philosophy majors and it includes discussions of several problems in the philosophy of logic.

Em termos semânticos, a consequência lógica é definida costumeiramente a partir do valor de verdade das premissas e conclusão: esta é verdadeira em toda situação na qual aquelas o sejam. Pode-se entender que, nestes casos, a conclusão não contém mais informação do que o conjunto de premissas. Com base nesta ideia, desenvolvemos, neste artigo, uma definição de consequência lógica informacional, baseada na noção de informação sugerida na Teoria Matemática da Comunicação. Mostramos alguns resultados, tais como que, apesar de (...) inconsistente, o sistema subjacente a essa noção não é trivial e que a lógica subjacente à consequência lógica informacional não é clássica, mas algum tipo de lógica paraconsistente. (shrink)

This essay proposes and defends a general thesis concerning the nature of fallacies of reasoning. These in distinctive ways are all said to be deductively invalid. More importantly, the most accurate, complete and charitable reconstructions of these species and specimens of the informal fallacies are instructive with respect to the individual character of each distinct informal fallacy. Reconstructions of the fallacies as deductive invalidities are possible in every case, if deductivism is true, which means that in every case (...) they should be formalizable in an expressively comprehensive formal symbolic deductive logic. The general thesis is illustrated by a detailed examination of Walter Burleigh's paradox in his c. 1323 work, De Puritate Artis Logicae Tractatus Longior (Longer Treatise on the Purity of Logic), as a challenge to the deductive validity of hypothetical syllogism. The paradox has the form, ‹If I call you a swine, then I call you an animal; if I call you an animal, then I speak truly; therefore, if I call you a swine, then I speak truly'. Several solutions to the problem are considered, and the inference is exposed as an instance of the common deductive fallacy of equivocation. (shrink)

In the first place, we present the definition and fundamental properties of information functions — functions which establish a correspondence between sets of formulas and the information contained in them. The intuitions for the notion of information stem from the conception of Bar-Hillel and Carnap in [3]. In § 2 we will briefly show how those notions can be applied to the logic of theory change. In § 3 we will use them for proving two theorems about the lattices of (...) classical subtheories and their content. (shrink)

Proceedings of the Tenth Brazilian Conference on Mathematical Logic. Coleção CLE, volume 14, 1995. Centro De Lógica, Epistemologia e História da Ciência, Unicamp, Campinas, SP, Brazil.

In this paper, we give an algebraic completeness theorem for constructive logic with strong negation in terms of finite rough set-based Nelson algebras determined by quasiorders. We show how for a quasiorder R, its rough set-based Nelson algebra can be obtained by applying Sendlewski’s well-known construction. We prove that if the set of all R-closed elements, which may be viewed as the set of completely defined objects, is cofinal, then the rough set-based Nelson algebra determined by the quasiorder R forms (...) an effective lattice, that is, an algebraic model of the logic E 0, which is characterised by a modal operator grasping the notion of “to be classically valid”. We present a necessary and sufficient condition under which a Nelson algebra is isomorphic to a rough set-based effective lattice determined by a quasiorder. (shrink)

The temporal updating of an agent’s beliefs in response to a flow of information is modeled in a simple modal logic that, for every date t, contains a normal belief operator B t and a non-normal information operator I t which is analogous to the ‘only knowing’ operator discussed in the computer science literature. Soundness and completeness of the logic are proved and the relationship between the proposed logic, the AGM theory of belief revision and the notion of plausibility is (...) discussed. (shrink)

A conception of an information system has been introduced by Pawlak. The study has been continued in works of Pawlak and Orlowska and in works of Vakarelov. They had proposed some basic relations and had constructed a formal system of a modal logic that describes the relations and some of their Boolean combinations. Our work is devoted to a generalization of this approach. A class of relation systems and a complete calculus construction method for these systems are proposed. As a (...) corollary of our main result, our paper contains a solution of a Vakarelov's problem: how to construct a formal system that describes all the Boolean combinations of the basic relations. (shrink)

Three different types of interdependence between pieces of information, or "secrets", are discussed and compared. Two of them, functional dependence and non-deducibility, have been studied and axiomatized before. This article introduces a third type of interdependence and provides a complete and decidable axiomatization of this new relation.

The dialogical games introduced in Jaakko Hintikka, Information-Seeking Dialogues: A Model, (Erkenntnis, vol. 14, 1979) are studied here to answer the question as to what the natural logic or the logic of natural language is. In a natural language certain epistemic elements are not explicitly indicated, but they determine which inference rules are valid. By means of dialogical games, the question is answered: all classical first-order rules have to be modified in the same way in which some of them are (...) modified in the transition to intuitionistic logic. (Furthermore, in some cases quantificational rules have to be modified further.) The rules that are left unmodified by intuitionists are applicable only to the output of certain game rules, but not to others. In. this sense, neither classical nor yet intuitionistic logic is the logic of natural language. We need a new type of nonclassical logic, justified by our information-seeking dialogues. (shrink)

In 1995, the Flemish Government commissioned a two wave panel study on the citizens knowledge about the Flemish institutions, structures, and policy, and on the effect of an intensive information campaign held between the first and the second wave. 710 respondents co-operated in thefirst wave. In 1996 the study was repeated, following a simulated test-re-test design with 532 panel respondents and 455 new respondents. This study is based on the 987 respondents in the 1996 survey. After a discussion of the (...) theoretical models for political knowledge, a model with eight latent variables and with a number of social-background variables is introduced and tested, using a structural modeling approach. The model has a strong predictive power for political knowledge. The most important explanatory variables are education, and reading political news in newspapers. Other explanatory factors for the variation in political knowledge are generation, and membership of voluntary associations, gender, individualism, and reading local news. The 'consumption' of local news or sensational news about crimes or calamities has a negative effect on political knowledge.The lack of political knowledge clearly affects both trust in polities and the experience of a complex incomprehensible society. The less the knowledge the more distrust and feelings of uncertainty. These relationships clearly show the importance ofknowledge about politics for the quality of democracy. (shrink)

Most, perhaps all, non-classical logics are a blend of classical logic with extralogical elements. Possibly this thesis has no general proof, and only a casuistic argument can be provided. I discuss a case of paraconsistency that results of applying a “filter” to two syllogistics. These syllogistics incorporate two ideas of Nikolai Vasiliev: the idea of a complete system of contrary judgements, and the idea of double judgements. I also show how these results can be extended to propositional logic, with the (...) aid of the conjunctive and disjunctive normal forms. Despite the non-classical appearance, it is used, without exception, the classical notion of deductive validity: a conclusion cannot carry more information, but may carry less information than the information carried by the collection of the premisses. (shrink)

In the paper we define a class of languages for representation o knowledge in those application areas when a complete information about a domain is not available. In the languages we introduce modal operators determined by accessibility relations depending on parameters.

Many different approaches to describing the players’ knowledge and beliefs can be found in the literature on the epistemic foundations of game theory. We focus here on non-probabilistic approaches. The two most prominent are the so-called Kripkeor Aumann- structures and knowledge structures (non-probabilistic variants of Harsanyi type spaces). Much of the recent work on Kripke structures has focused on dynamic extensions and simple ways of incorporating these. We argue that many of these ideas can be applied to knowledge structures as (...) well. Our main result characterizes precisely when one type can be transformed into another type by a specific type of information update. Our work in this paper suggest that it would be interesting to pursue a theory of “information dynamics” for knowledge structures (and eventually Harsanyi type spaces). (shrink)

Este libro estudia cuestiones pertenecientes al campo de la lógica aplicada, concretamente de teoría de la argumentación informal. Abarca el análisis de los principales tipos de errores por incom­petencia argumentativa a partir de un enfoque nor­mativo actualizado y con una propuesta de taxono­mía de falacias lógicas informales basada en los cri­terios básicos de buena argumentación. Se identifi­can, describen y ejemplifican, con textos de varios niveles de dificultad, las falacias más habituales (en­tre ellas, las falacias «ad hominem, ad populum, (...) petitio principii», por inducción precipitada, falsa analogía, falso dilema) presentes en diferentes interacciones lin­güísticas interpersonales (documentos políticos, pe­riodísticos, pseudocientíficos, filosóficos) formu­ladas en lenguajes naturales. A lo largo del libro, los principales epígrafes se ilustran con textos extraídos del «Quijote» y de obras de Lewis Carroll. En los capí­tulos iniciales se abordan asuntos previos recomen­dables para la buena comprensión de los capítulos de desarrollo de falacias específicas, a saber, la re­la­ción entre lógica y retórica, los distintos tipos de ar­gumentos, la relación entre razonar y argumentar, el lugar de las emociones en la argumentación falaz y las distintas teorías y definiciones de falacia, así como los errores conceptuales más comunes asociados con el término o el vínculo entre falacias y paradojas. Se re­servan dos capítulos finales, uno sobre falacias bioéticas contemporáneas, y otro con una propuesta de «Código de Buenas Prácticas Argumentativas», fun­damentado en los criterios a partir de los que se ela­bora la taxonomía de falacias del libro. (shrink)

We study a simple game theoretic model of information transfer which we consider to be a baseline model for capturing strategic aspects of epistemological questions. In particular, we focus on the question whether simple learning rules lead to an efficient transfer of information. We find that reinforcement learning, which is based exclusively on payoff experiences, is inadequate to generate efficient networks of information transfer. Fictitious play, the game theoretic counterpart to Carnapian inductive logic and a more sophisticated kind of learning, (...) suffices to produce efficiency in information transfer. (shrink)

Este trabajo tiene como fin revisar los informes sobre derechos humanos en Colombia de la Oficina del Alto Comisionado de las Naciones Unidas para los Derechos Humanos, en busca de evidencia que demuestre la interrelación anulativa de los actores sociales del conflicto armado en contra de la dignidad de las victimas. La violencia y todo acto de terrorismo emergente del conflicto armado aumentan la vulnerabilidad, el silenciamiento de la memoria, la impunidad y, en gran medida, promueve una lógica evasiva (...) de responsabilidades y reparaciones que son necesarias para esclarecer los hechos victimizantes y otorgar voz a los afectados. El conflicto armado sume a las víctimas en una dinámica del terror que impacta todas sus áreas de desarrollo y limita su sentido de seguridad, confianza y credibilidad en el otro y en las instituciones sociales. (shrink)

In this article we investigate the family of independence-friendly (IF) logics in the equality-free setting, concentrating on questions related to expressive power. Various natural equality-free fragments of logics in this family translate into existential second-order logic with prenex quantification of function symbols only and with the first-order parts of formulae equality-free. We study this fragment of existential second-order logic. Our principal technical result is that over finite models with a vocabulary consisting of unary relation symbols only, this fragment of second-order (...) logic is weaker in expressive power than first-order logic (with equality). Results about the fragment could turn out useful for example in the study of independence-friendly modal logics. In addition to proving results of a technical nature, we address issues related to a perspective from which IF logic is regarded as a specification framework for games, and also discuss the general significance of understanding fragments of second-order logic in investigations related to non-classical logics. (shrink)

We address the issue of manipulating games through communication. In the specific setting we consider (a variation of Boolean games), we assume there is some set of environment variables, the values of which are not directly accessible to players; the players have their own beliefs about these variables, and make decisions about what actions to perform based on these beliefs. The communication we consider takes the form of (truthful) announcements about the values of some environment variables; the effect of an (...) announcement is the modification of the beliefs of the players who hear the announcement so that they accurately reflect the values of the announced variables. By choosing announcements appropriately, it is possible to perturb the game away from certain outcomes and towards others. We specifically focus on the issue of stabilisation: making announcements that transform a game from having no stable states to one that has stable configurations. (shrink)

In this paper we present two types of logics and \ ) where certain p-adic functions are associated to propositional formulas. Logics of the former type are p-adic valued probability logics. In each of these logics we use probability formulas K r,ρ α and D ρ α,β which enable us to make sentences of the form “the probability of α belongs to the p-adic ball with the center r and the radius ρ”, and “the p-adic distance between the probabilities of (...) α and β is less than or equal to ρ”, respectively. Logics of the later type formalize processes of thinking where information are coded by p-adic numbers. We use the same operators as above, but in this formalism K r,ρ α means “the p-adic code of the information α belongs to the p-adic ball with the center r and the radius ρ”, while D ρ α,β means “the p-adic distance between codes of α and β are less than or equal to ρ”. The corresponding strongly complete axiom systems are presented and decidability of the satisfiability problem for each logic is proved. (shrink)