his paper presents a unified treatment of the propositional and first-order many-valued logics through the method of tableaux. It is shown that several important results on the proof theory and model theory of those logics can be obtained in a general way. We obtain, in this direction, abstract versions of the completeness theorem, model existence theorem (using a generalization of the classical analytic consistency properties), compactness theorem and Lowenheim-Skolem theorem. The paper is completely self-contained and includes examples of application to (...) particular many-valued formal systems. (shrink)

After a brief promenade on the several notions of translations that appear in the literature, we concentrate on three paradigms of translations between logics: ( conservative ) translations , transfers and contextual translations . Though independent, such approaches are here compared and assessed against questions about the meaning of a translation and about comparative strength and extensibility of a logic with respect to another.

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.

First published in 1969, this was a new assessment of Freud’s most creative years and the formative period in psychoanalysis and was the first book to attempt a systematic presentation of Freud’s early ideas, relating them to his later work and to contemporary psychoanalysis. During the years 1888-1898 Freud published 15 papers and one book. In addition many of his ideas were formulated in a series of letters and drafts that he wrote to Dr Wilhelm Fliess. This material provided new (...) insights into the nature of Freud’s creative genius and gave new meaning to his published works. Psychoanalysis: The First Ten Years reviews these early papers, drafts and letters, and describes tentative formulations that, in spite of their value, were not developed further because of lack of time or a shift in interest. As Dr Stewart observes, ‘the study of this aspect of Freud’s work is perhaps the most exciting. Freud’s creativity in these years was remarkable. The ideas he _discarded_ in this short period of time would, for a less gifted person, have been a full life’s work of which he could have been proud.’ There is a good deal of historical and literary interest in his account of Freud’s relationships with Fliess, Breuer and others, but the core of the book is the critical assessment and systematic presentation of Freud’s early major insights, which dramatically reveal a creative genius in the process of discovery. (shrink)

There is no doubt that soybean is the most important crop for Argentina, with a planted surface that rose 11,000,000 hectares and a production of around 35,000,000 metric tons. During the 1990s, there was a significant agriculture transformation in the country, motorize by the adoption of transgenic crops (soy-bean, maize, and cotton) under the no-tillage system. The expansion of this model has been spread not only in the Pampas but also in very rich areas with high biodiversity, opening a new (...) agricultural border to important eco-regions like the Yungas, Great Chaco, and the Mesopotamian Forest. Transgenic cropping is a powerful technology. This produced relevant transformations over the environment and society where it is allowed. Migration, concentration of agribusiness, and loss of food sovereignty are some of the social results. Landscape transformation in the rural sector is evident, and the appearance of tolerance weeds to glyphosate is a reality. Nutrient depletion, soil-structure degradation, potential desertification, and loss of species are other consequences on the environmental level. (shrink)

The economically successful model of industrial agriculture that is currently expanding throughout Argentina is leading to deep social, economic, environmental, and logistical changes that are seriously restricting the sustainability of the rural, urban and environmental systems. The transformation of activities, the arrival of new technologies, the arrival of organizations with large financial and technological capabilities, the displacement of hundreds of thousands of small-scale and medium-scale farmers and their reallocation to new productive functions are not only affecting the social sustainability of (...) the rural sector but are affecting the urban communal plots of villages and towns located on the Chacopampeana Plain. Now, the production of agrofuels as a response to international global demand will promote the ecological and social depletion that Argentina has been facing from the beginning of the 1990s. We argue in terms of ecological economics that externalities should be included in the costs of companies, not just economic costs. (shrink)

Attempts to comprehend the traumatic significance of Hiroshima in order to construct a new theory of history.

The bulk of the DNA in eukaryotic chromatin behaves as if it is topologically relaxed; however, a subfraction can be shown to be under suercoil tension. Endonuclease S1 cuts at specific hypersentive sites in chromatin (in the promoter regions of active genes) and this enzyme cuts in the same region in supercoiled plasmids, but not in relaxed or linearized molecules. A subfraction of the minichromosomes formed after SV40 infection or microinjection of plasmid DNA into oocytes contains supercoil tension and this (...) subfraction is thought to play an important role in transcription. (shrink)

This paper investigates a problem related to quantifiers which has some analogies to that of propositional completeness I give a definition of quantifier in many-valued logics generalizing the cases which already occur in first order many- valued logics. Though other definitions are possible, this particular one, which I call distribution quantifiers, generalizes the classical quantifiers in a very natural way, and occurs in finite numbers in every m-valued logic. We then call the problem of quantificationa2 completeness in m-valued logic the (...) problem of characterizing which are the quantifiers in a given language which can generate all other quantifiers in this language, using the connectives, as is the case, for example, of the universal and exis- tential quantifiers in classical logic, using negation. We are interested, in particular, in those many-valued quantifiers which closely mimic the behavior of existential an universal quantifiers in generating all other quantifiers using negation: these I call perfect quantifiers, as defined below. The main result of this paper is the characterization of all perfect quantifiers in 3-valued logics, which are complete if the logic is functionally complete. As a byproduct, we obtain the same result for the classical logic, which we include mainly for motivation. (shrink)

First Published in 1999. Routledge is an imprint of Taylor & Francis, an informa company.