From a conception of philosophy that breaks with the philosophical tradition, Wittgenstein presents a human being perspective that surpasses the classic dichotomy between body and soul, legacy by Modernity, when thinking of it as an integrated whole, a psychophysical unit. This understanding is possible thanks to the understanding of philosophy as an activity and not as a theory. At first, the philosopher understood that this activity was limited to the logical analysis of language; however, considering the insufficient approach to dissolve (...) philosophical problems, he gradually adopts the grammatical analysis of ordinary language, which turns to the uses of linguistic expressions, in order to identify the rules that guide the use of words with meaning. And so, attentive to linguistic practices, he understands that the human being is not divided into parts, but, on the contrary, that body and soul constitute a single reality. What is internal to the subject becomes visible through the external from its behavior in the world, and this is how the human being can be understood according to Wittgenstein. Considering that the Wittgensteinian conception of human being is an offshoot of his concept of philosophy, the article first presents the development of his understanding of philosophy to then detail the concept of human being that constitutes and is understood through the language itself. (shrink)

Background: The new human coronavirus that leads to COVID-19 has spread rapidly around the world and has a high degree of lethality. In more severe cases, patients remain hospitalized for several days under treatment of the health team. Thus, it is important to develop and use technologies with the aim to strengthen conventional therapy by encouraging movement, physical activity, and improving cardiorespiratory fitness for patients. In this sense, therapies for exposure to virtual reality are promising and have been shown to (...) be an adequate and equivalent alternative to conventional exercise programs.Aim: This is a study protocol with the aim of comparing the conventional physical therapy intervention with the use of a non-immersive VR software during COVID-19 hospitalization.Methods: Fifty patients hospitalized with confirmed diagnosis of COVID-19 will be divided in two groups under physiotherapy treatment using conventional or VR intervention: Group A: participants with COVID-19 will start the first day of the protocol with VR tasks in the morning and then in the second period, in the afternoon, will perform the conventional exercises and Group B: participants with COVID-19 will start the first day with conventional exercises in the morning and in the second period, in the afternoon, will perform activity with VR. All participants will be evaluated with different motor and physiologic scales before and after the treatment to measure improvements.Conclusion: Considering the importance of benefits from physical activity during hospitalization, VR software shows promise as a potential mechanism for improving physical activity. The results of this study may provide new insights into hospital rehabilitation.Trial Registration:ClinicalTrials.gov, identifier: NCT04537858. Registered on 01 September 2020. (shrink)

Introdução: as inovações tecnológicas que surgem no contexto dos Arquivos estão diretamente ligadas à sua capacidade de evolução e adaptação. Descobrir e estudar quais dessas novas tecnologias podem ser mais bem aproveitadas nos Arquivos pode ser a diferença entre evoluir ou padecer. Objetivo: mapear as tendências recentes encontradas na literatura científica sobre as mudanças que estão ocorrendo nos Arquivos. Metodologia: foi realizada uma revisão de literatura, para determinar as principais tendências encontradas na literatura científica recente, a partir do ano de (...) 2015, sobre as inovações e mudanças que têm ocorrido nos Arquivos. Resultados: observa que alguns aspectos de destaque no que concerne às Arquivos do futuro: evolução da web, makerspaces, redes sociais e mudança no perfil do profissional que trabalha com Arquivos. Conclusões: O futuro dos Arquivos é ainda incerto, mas aponta em algumas direções, e é definitivamente digital, com acesso universal, porém não gratuito, também admite a esfera de social, interativa e vivo em constante evolução, uma evoluir bem mais rápido e dinâmico do que o observado no século XX. (shrink)

Soccer players inescapably live under stress during the sportive career, and many real-life aspects of soccer situations operate in the ongoing performance. This study’s main objective was to elaborate the List of Stressors in Professional Indoor and Field Soccer, a self-report instrument designed to measure the impact of 77 soccer situations upon the sport performance. Participants were 138 indoor and field soccer players from the Brazilian Premier League. Each situation was evaluated on a 7-point scale, ranging from the most negative (...) to the most positive. Data were analyzed according to the players’ perception of the items: distress or eustress and its intensity, and after that, situations perceived as plus −1 and +1 were compared by time in which they were experienced and distributed among five categories established by the literature: Expectations about the Performance, Personal Factors, Competition Aspects, Training Demands, and Relationship with Significant People. Narratives of athletes’ experiences were also used to discuss the results. An Exploratory Structural Equation Modeling using Bi-factorial was employed to assess the factor structure. For the total participants, 49 situations were perceived as distress and 28 as eustress. Using the criteria established a priori, the distribution was among the five categories in the remaining 32 situations. Differences in perception between less and more experienced players were found in 11 situations. The results revealed that Brazilian professional soccer players experience various stressful situations. These events are important representations of environmental demands and could predict the performance as they are perceived as eustress or distress. Some of these stressful situations are inherent in sport and others adjacent to the sports system or environment. Coach pressure to win and conflicts with teammates are examples of stressors in-sport, family problems and disputes with press or fans are examples of stressors external to the team, also called peripheral opponents, and showed the relative social influence of significant others in soccer performance. We can conclude that the knowledge of the direction of a given stress situation has important practical implications in preparing athletes and helping them face the performance stressors that are part of soccer daily life. (shrink)

The concept of substance is considered fundamental in order to understand chemistry and other related concepts, but many problems have been reported about its learning process. Considering the importance of textbooks in the training of chemistry teachers, this study aimed to identify the concepts of substance in general chemistry textbook glossaries. In addition, the study assessed the concepts of substance in relation to other chemical concepts and, when available, compared them with the concepts established by the IUPAC. The methodology employed (...) was content analysis and the results showed that concepts and statements related to the term ‘substance’ are different in the general chemistry textbooks analyzed. They also differ from those stated by IUPAC. Furthermore, it was found that many concepts are dependent on the concept of substance. It is concluded that there must be a greater effort from the community of chemists and the teaching of chemistry in the search for conceptual uniformity to reduce the problems of conceptual understanding. (shrink)

IntroductionRegular exercise has long been shown to positively impact the immune system responsiveness and improve mental well-being. However, the putative links between biomarkers of mental health and immune efficiency in exercising subjects have been scarcely investigated. The aim of this study was to verify the effect of a 14-week combined chair-based exercise program on salivary steroid hormones and anti-microbial proteins, functional fitness, and MWB indexes in pre-frail older women.MethodsThe participant women were randomly divided into the exercising group and the non-exercising (...) control group. The pre/post assessment included: salivary anti-microbial proteins lysozyme; and immunoglobulin-A ; salivary steroid hormones of testosterone and cortisol ; functional fitness ; MWB questionnaires.ResultsSignificant differences with large Cohen’s effect sizes were found on increased salivary TT after exercise intervention. The results revealed a decrease in IgA levels after CEP. The increase in subjective happiness levels and decrease of stress perception and depressive state were found after intervention in the CEP group. Robust statistical differences in gait speed and balance tests were also found in the CEP group. In control, COR increased moderately while no changes were found for the other indicators. Correlation analyses showed inter-dependence between pre–post variations of MWB, biochemical indexes, and fitness function.ConclusionThe CEP program was able to improve functional-fitness performance, decrease feelings of stress, and increase happiness. The CEP also induced clinically relevant hormonal and immune responses, which suggests that chair exercises that combine muscular strength, balance, and gait speed training are promising interventions to improve physical and mental health of older pre-frail adults. (shrink)

O Brasil, diz Millôr Fernandes, tem um enorme passado pela frente e, esse projeto de nação ergue-se com a memória coletiva. Nessa via, o objetivo do estudo é analisar bibliometricamente como a temática ‘memória coletiva’ se apresenta indexada no acervo da literatura científica da Ciência da Informação - Brapci. A pesquisa estabelece métricas sobre o quantitativo anual de publicações, os periódicos e os autores envolvidos, as palavras chaves mais frequentes. Estabelecido o recorte dos últimos dez anos completos, são recuperados 50 (...) artigos. O diagnóstico nota a sustentabilidade da produção científica relacionada ao tema memória coletiva e, com o debate das práticas patrimoniais e memorialistas alinham-se ações em prol da visibilidade, do acautelamento e da proteção do Patrimônio Cultural. Conclui-se que entre os anos de 2017 e 2021 a temática memória coletiva adentra na Ciência da Informação, cingindo construtos em prol da ética, da transparência e dos direitos humanos. A temática processa amplas provocações e reflexões que, por meio das narrativas da memória e do esquecimento estão ligadas ao status teórico-linguístico inerente às interfaces do Ser Informação. (shrink)

The rating of perceived exertion can be used to monitor the exercise intensity during laboratory and specific tests, training sessions, and to estimate the internal training load of the athletes. The aim of the present study was to develop and validate a specific pictorial perceived exertion scale for soccer players called GOAL Scale. The pictorial GOAL Scale was validated for twenty under-17 soccer players. In the validation phase, the athletes were evaluated in a progressive protocol involving stimuluses of 3 min (...) with 1 min for the rest into the stages until the voluntary exhaustion in Maximal Cardiopulmonary Effort Test, and in the Yo Yo Intermittent Recovery Test – Level 1. The RPE identified by the GOL Scale, by the Borg Scale 6 – 20 and by the Cavasini Scale, as well as the heart rate, perceptual of the heart rate and the blood lactate concentration were immediately evaluated after each stage of both tests. Spearman’s correlation coefficient was used. Construct scale validity was examined by regressing GOAL Scale against Borg Scale 6 – 20 and Cavasini Scale and concurrent scale validity was investigated by regressing GOAL Scale against HR, beats/min and blood lactate concentration during two progressive tests. There was a significant correlation values of the GOAL Scale with Borg Scale, Cavasini Scale, %HRmax, HR and lactate during tests. The results evidenced concurrent and construct validity of the GOAL Scale across a wide range of exercise intensity. The absence of verbal anchors makes the use of this instrument to soccer, futsal and beach soccer athletes of different languages and different literacy levels possible. (shrink)

Inicialmente, o texto indaga sobre o significado do exercício do filósofo social; pretende também localizar as origens do debate moderno sobre ‘subjetividade’ no pensamento filosófico e social. As idéias norteadoras de Kant, se situam na confluência e na disjunção entre razão (conhecimento) e subjetividade (moral). A partir dessa referência, o debate entre alguns pensadores considerados como pós-modernos (Badiou e Zizek), por um lado, e por outro Castoriadis que recusa esta nomenclatura, vão derivando idéias novas sobre ‘sujeito’ e ‘verdade’. Esse debate (...) não é sem conseqüências para a teoria sociológica que assume para si o desafio de introduzir a categoria de ‘sujeito’ em seus cânones (Touraine). As reflexões de Stengers servem também para questionar e aproximar as práticas da produção do conhecimento e dos discursos científicos. Finalmente, restam desafios para se pensar teorias e práticas sócio-ambientais à luz desses conceitos apresentados ao longo do texto. (shrink)

The basic principles of scientific research from the great French physiologist whose contributions in the 19th century included the discovery of vasomotor nerves; nature of curare and other poisons in human body; more.

No cinema brasileiro recente, o diálogo entre o documentário e a ficção tem merecido destaque, com produções de baixo orçamento e ideias originais. É o caso de Santiago (João Moreira Salles, 2007) e Viajo Porque Preciso, Volto Porque Te Amo (Marcelo Gomes, Karim Aïnouz, 2009), filmes que trabalham esse diálogo de forma sutil e diegética, ressignificando imagens de um arquivo próprio, pessoal.

O manuscrito clandestino Jordanus Brunus redivivus ou Traité des erreurs populaires foi publicado em 1771, não trazendo indicação alguma de sua autoria. Entretanto, a despeito do anonimato da obra, ela tornou-se um dos textos mais famosos dentre a filosofia clandestina do século XVIII, aludindo a um filósofo que foi uma das maiores vítimas da superstição e do fanatismo de sua época: Giordano Bruno. O título do escrito é uma espécie de homenagem ao pensador italiano, mas não há no decorrer da (...) obra uma menção sequer que comprove que o autor anônimo tenha lido uma linha de suas obras, mesmo que seja considerado o elo filosófico de união entre o brunismo da primeira metade do século XVII e o da segunda metade do século XVIII. É em um encadeamento de ideias progressivo no Jordanus Brunus que nos permite encontrar o fio condutor das reflexões do autor: a sua formulação do ateísmo caracteriza-se por sua abordagem não dogmática, dissimulada, preparando o solo para o racionalismo ateu que estaria por vir. O presente artigo limitar-se-á à terceira e quarta partes do manuscrito, nas quais o autor anônimo vai tratar diretamente da questão da existência de deus e fazer diversas objeções às provas de sua existência. (shrink)

Soren Kierkegaard's Works of Love, a series of deliberations on the commandment to love one's neighbor, has often been condemned by critics. Here, Ferreira seeks to rehabilitate Works of Love as one of Kierkegaard's most important works. He shows that Kierkegaard's deliberations on love are highly relevant to some important themes in contemporary ethics, including impartiality, duty, equality, mutuality, reciprocity, self-love, sympathy, and sacrifice. Ferreira also argues that Works of Love bears on issues peculiar to a religious ethic, (...) such as the role of God as "middle term," and the possibility of preserving the aesthetic dimensions of love in a religious ethic of relation. (shrink)

We propose an account of dynamic predicates which draws on the notion of force, eliminating reference to events in the linguistic semantics. We treat dynamic predicates as predicates of forces, represented as functions from an initial situation to a final situation that occurs ceteris paribus, that is, if nothing external intervenes. The possibility that opposing forces might intervene to prevent the transition to a given final situation leads us to a novel analysis of non-culminating accomplishment predicates in a variety of (...) languages, including the English progressive. We then apply the force-theoretic framework to the composition of basic Vendlerian eventuality types within a lexical-decomposition syntax. The difference between predicates of forces and predicates of situations is argued to underlie the dynamic/stative contrast, and also to allow for a formal treatment of the difference between be and stay. Consequences for the relationship between language and cognition are discussed. (shrink)

The Picturesque (a set of theories, ideas, and conventions which grew up around the question of how we look at landscape) offers a valuable focus for new investigations into the literary, artistic, social, and cultural history of the late eighteenth and nineteenth centuries. This volume of essays by scholars from various disciplines in Britain and America incorporates a range of historically and theoretically challenging approaches to the topic. It covers the writers most closely identified with the exposition of the Picturesque (...) as a theory, and also traces the influence and implications of its aesthetic in a variety of fields in the Romantic period, including literary and pictorial works, estate management, and women's fashion. Several essays deal more specifically with radical critiques and appropriations of the Picturesque in the nineteenth century, while in others, its influence is traced beyond traditionally accepted geographical or historical bounds. (shrink)

Multialgebras have been much studied in mathematics and in computer science. In 2016 Carnielli and Coniglio introduced a class of multialgebras called swap structures, as a semantic framework for dealing with several Logics of Formal Inconsistency that cannot be semantically characterized by a single finite matrix. In particular, these LFIs are not algebraizable by the standard tools of abstract algebraic logic. In this paper, the first steps towards a theory of non-deterministic algebraization of logics by swap structures are given. Specifically, (...) a formal study of swap structures for LFIs is developed, by adapting concepts of universal algebra to multialgebras in a suitable way. A decomposition theorem similar to Birkhoff’s representation theorem is obtained for each class of swap structures. Moreover, when applied to the 3-valued algebraizable logics J3 and Ciore, their classes of algebraic models are retrieved, and the swap structures semantics become twist structures semantics. This fact, together with the existence of a functor from the category of Boolean algebras to the category of swap structures for each LFI, suggests that swap structures can be seen as non-deterministic twist structures. This opens new avenues for dealing with non-algebraizable logics by the more general methodology of multialgebraic semantics. (shrink)

This paper seeks to differentiate negative properties from positive properties, with the aim of providing the groundwork for further discussion about whether there is anything that corresponds to either of these notions. We differentiate negative and positive properties in terms of their functional role, before drawing out the metaphysical implications of proceeding in this fashion. We show that if the difference between negative and positive properties tabled here is correct, then negative properties are metaphysically contentious entities, entities that many philosophers (...) will be unwilling to countenance. (shrink)

The increasing use of digital technologies in judicial and arbitration proceedings increases the usage of digital evidence by the parties, which brings the necessity of creating patterns for adjudicators to admit and assess this new type of evidence. This paper generally addresses digital evidence focusing on the second moment in international arbitration proceedings. It also narrows the topic to hacked and leaked evidence and its admissibility in international arbitration. The literature review showed a significant amount of research devoted to the (...) evidence in arbitration. Some considered electronic evidence within one jurisdiction; others focused on certain forms of digital evidence such as electronic signatures. Papers on digital evidence in international arbitration approach arbitration rules for digital evidence but skip admissibility issues. No systemic and complex works research digital evidence in arbitration, explicitly focusing on the admissibility of hacked and leaked digital evidence from a comparative perspective. Also, no research deals with enforcing international arbitration awards relying on illegally obtained digital evidence. In these cases, there could be a possible violation of domestic public policy under the New York Convention terms (art. V, 2, b). That is why the paper aims to offer the concept of digital evidence in international arbitration, including hacked and leaked evidence, criteria of its admissibility and relevance, and design the arbitration guidelines for assessing hacked and leaked evidence. Comparative legal analysis of the international arbitration rules and national procedure law allowed us to compare the regulatory approaches to the definition of digital evidence and its admissibility worldwide. The method of legal modeling allowed designing model guidelines for arbitral tribunals to evaluate the admissibility and relevance of digital evidence, including hacked and leaked evidence. Moreover, the case study method allowed us to analyze jurisprudence and define criteria for admission of hacked and leaked evidence. We conclude that the admissibility of hacked and leaked evidence depends solely on the arbitrator’s broad discretion to assess the evidence. Nevertheless, thorough evidence analysis and a well-reasoned award are always mandatory. (shrink)

Despite being fairly powerful, finite non-deterministic matrices are unable to characterize some logics of formal inconsistency, such as those found between mbCcl and Cila. In order to overcome this limitation, we propose here restricted non-deterministic matrices (in short, RNmatrices), which are non-deterministic algebras together with a subset of the set of valuations. This allows us to characterize not only mbCcl and Cila (which is equivalent, up to language, to da Costa's logic C_1) but the whole hierarchy of da Costa's calculi (...) C_n. This produces a novel decision procedure for these logics. Moreover, we show that the RNmatrix semantics proposed here induces naturally a labelled tableau system for each C_n, which constitutes another decision procedure for these logics. This new semantics allows us to conceive da Costa's hierarchy of C-systems as a family of (non deterministically) (n+2)-valued logics, where n is the number of "inconsistently true" truth-values and 2 is the number of "classical" or "consistent" truth-values, for every C_n. (shrink)

Moonlighting – the performance of more than one function by a single protein – is becoming recognized as a common phenomenon with important implications for systems biology and human health. The different functions of a moonlighting protein may use different regions of the protein structure, or alternative structures that occur due to post-translational modifications and/or differences in binding partners. Often the different functions of moonlighting proteins are used at different times or in different places. The existence of moonlighting functions complicates (...) efforts to under- stand metabolic and regulatory networks, as well as physiological and pathological processes in organisms. Because moonlighting functions can play important roles in disease processes, an improved understanding of moonlighting proteins will provide new opportunities for pharmacological manipulations that specifically target a function involved in pathology while sparing physiologically important functions. (shrink)

Judging a person as morally responsible involves believing that certain responses (such as punishment, reward, or expressions of blame or praise) can be justifiably directed at the person. This paper develops an account of the evolution of moral responsibility judgment that adopts Michael Tomasello’s two-step theory of the evolution of morality and borrows also from Christopher Boehm’s work. The main hypothesis defended is that moral responsibility judgment originally evolved as an adaptation that enabled groups of cooperative individuals to hold free (...) riders responsible more safely by acting in a coordinated way. (shrink)

The logics of formal inconsistency (LFIs, for short) are paraconsistent logics (that is, logics containing contradictory but non-trivial theories) having a consistency connective which allows to recover the ex falso quodlibet principle in a controlled way. The aim of this paper is considering a novel semantical approach to first-order LFIs based on Tarskian structures defined over swap structures, a special class of multialgebras. The proposed semantical framework generalizes previous aproaches to quantified LFIs presented in the literature. The case of QmbC, (...) the simpler quantified LFI expanding classical logic, will be analyzed in detail. An axiomatic extension of QmbC called QLFI1o is also studied, which is equivalent to the quantified version of da Costa and D'Ottaviano 3-valued logic J3. The semantical structures for this logic turn out to be Tarkian structures based on twist structures. The expansion of QmbC and QLFI1o with a standard equality predicate is also considered. (shrink)

In 1988, J. Ivlev proposed some (non-normal) modal systems which are semantically characterized by four-valued non-deterministic matrices in the sense of A. Avron and I. Lev. Swap structures are multialgebras (a.k.a. hyperalgebras) of a special kind, which were introduced in 2016 by W. Carnielli and M. Coniglio in order to give a non-deterministic semantical account for several paraconsistent logics known as logics of formal inconsistency, which are not algebraizable by means of the standard techniques. Each swap structure induces naturally a (...) non-deterministic matrix. The aim of this paper is to obtain a swap structures semantics for some Ivlev-like modal systems proposed in 2015 by M. Coniglio, L. Fariñas del Cerro and N. Peron. Completeness results will be stated by means of the notion of Lindenbaum–Tarski swap structures, which constitute a natural generalization to multialgebras of the concept of Lindenbaum–Tarski algebras. (shrink)

O presente trabalho procura se debruçar sobre a dimensão ontológica do homem animal-político-social em Aristóteles. Logo, desde já nos cabe ressaltar que a verificação do homem enquanto animal político-social abarcará um caráter metafísico para a efetivação no e do físico-material-natural, ou seja, o ser biopsicossocial. Refletindo, construindo e interligando o ser físico e “espiritual”. Portanto, o objeto principal será o que diz respeito ao homem como um animal político-social, no sentido ontológico do ser sensível em Aristóteles. Para tanto, a proposta (...) abarcará a Teoria das Quatro Causas de Aristóteles. Isso para demonstrar certa ontologia de uma suposta essência da ou na substancia no e do ser humano. Ou seja, quem é o “homem-ser-ente” coberto por sua estrutura física e sensível no sentido ontológico no corporal? São os seres humanos animais essencialmente políticos? E se forem são seres políticos do e ou no “espiritual”, “almático” e metafísico ou no físico-corporal? (shrink)

In 1986, Mikenberg et al. introduced the semantic notion of quasi-truth defined by means of partial structures. In such structures, the predicates are seen as triples of pairwise disjoint sets: the set of tuples which satisfies, does not satisfy and can satisfy or not the predicate, respectively. The syntactical counterpart of the logic of partial truth is a rather complicated first-order modal logic. In the present article, the notion of predicates as triples is recursively extended, in a natural way, to (...) any complex formula of the first-order object language. From this, a new definition of quasi-truth is obtained. The proof-theoretic counterpart of the new semantics is a first-order paraconsistent logic whose propositional base is a 3-valued logic belonging to hierarchy of paraconsistent logics known as Logics of Formal Inconsistency, which was proposed by Carnielli and Marcos in 2002. (shrink)

Social animals need to share space and resources, whether sexual partners, parents, or food. Sharing is indeed at the core of social life. Humans, however, of all social animals, have distinct ways of sharing. They evolved to become Homo Negotiatus; a species that is prone to bargain and to dispute the value of things until some agreement is reached.

Our goal is to investigate the notion of self-agency in William James and Donald Winnicott. With James, we examine the descriptive element of what constitutes a self. With Winnicott, we explore his explanatory theory on self-emergence. Winnicott's perspective is presented here as the prehistory of the Jamesian self. James's conception of self is similar to the Winnicottian notion of an "integrated self", an embodied position that emerges from the organism's actions in the experiential field. The combination of the two approaches (...) leads to the idea that the self is a flux of identities emerging in interaction with others in the "transitional space" (an intermediate area of experience). (shrink)

Soren Kierkegaard's Works of Love, a series of deliberations on the commandment to love one's neighbor, has often been condemned by critics. Here, Ferreira seeks to rehabilitate Works of Love as one of Kierkegaard's most important works. He shows that Kierkegaard's deliberations on love are highly relevant to some important themes in contemporary ethics, including impartiality, duty, equality, mutuality, reciprocity, self-love, sympathy, and sacrifice. Ferreira also argues that Works of Love bears on issues peculiar to a religious ethic, (...) such as the role of God as "middle term," and the possibility of preserving the aesthetic dimensions of love in a religious ethic of relation. (shrink)

Suszko's Thesis maintains that many-valued logics do not exist at all. In order to support it, R. Suszko offered a method for providing any structural abstract logic with a complete set of bivaluations. G. Malinowski challenged Suszko's Thesis by constructing a new class of logics (called q-logics by him) for which Suszko's method fails. He argued that the key for logical two-valuedness was the "bivalent" partition of the Lindenbaum bundle associated with all structural abstract logics, while his q-logics were generated (...) by "trivalent" matrices. This paper will show that contrary to these intuitions, logical two-valuedness has more to do with the geometrical properties of the deduction relation of a logical structure than with the algebraic properties embedded on it. (shrink)

The aim of the paper is to analyze the expressive power of the square operator of Łukasiewicz logic: ∗x=x⊙x⁠, where ⊙ is the strong Łukasiewicz conjunction. In particular, we aim at understanding and characterizing those cases in which the square operator is enough to construct a finite MV-chain from a finite totally ordered set endowed with an involutive negation. The first of our main results shows that, indeed, the whole structure of MV-chain can be reconstructed from the involution and the (...) Łukasiewicz square operator if and only if the obtained structure has only trivial subalgebras and, equivalently, if and only if the cardinality of the starting chain is of the form n+1 where n belongs to a class of prime numbers that we fully characterize. Secondly, we axiomatize the algebraizable matrix logic whose semantics is given by the variety generated by a finite totally ordered set endowed with an involutive negation and Łukasiewicz square operator. Finally, we propose an alternative way to account for Łukasiewicz square operator on involutive Gödel chains. In this setting, we show that such an operator can be captured by a rather intuitive set of equations. (shrink)