SCOPE OF THE SERIESTrends in Logic is a bookseries covering essentially the same area as the journal Studia Logica -that is, contemporary formal logic and its applications and relations to other disciplines. These include artificial intelligence, informatics, cognitive science, philosophy of science, and the philosophy of language. However, this list is not exhaustive, moreover, the range of applications, comparisons and sources of inspiration is open and evolves over time.No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work.
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To CeciliaJust as the Z-module structure of ðG; 1Þ is missing in the MV-algebra A ¼ CðG; 1Þ; several fundamental notions and constructs available in the framework of MV-algebras and Łukasiewicz logic hardly make any sense for unital '-groups, despite the latter are categorically equivalent to MV-algebras. Thus, the equational definability of the class of MV-algebras gives us a way of introducing free and finitely presented objects-while the class of unital '-groups is not even definable vii in first-order logic. Induction on the complexity of Łukasiewicz formulas, combined with their geometric representation as McNaughton functions, is a main tool to explore syntactic and semantic consequence in Ł ? , and the fundamental logic property of interpolation. Formulas in Ł ? denote continuously valued events, just as boolean formulas denote yes-no events; coherent probability assessments on these events yield Rényi conditionals, which would make no sense for unital '-groups. r-complete MV-algebras provide a natural framework for generalizations of many classical results originally proved for r-complete boolean algebras, such as the theorem of Loomis-Sikorski and Poincaré's recurrence theorem. Several main techniques and results of probability theory, that Carathéodory reformulated in the language of r-complete boolean algebras, have nontrivial MV-algebraic generalizations. Bases originate as algebraically invariant counterparts of disjunctive Schauder normal forms in Łukasiewicz logic; an MV-algebra has a basis iff it is finitely presented. Classical first-order logic with identity has a generalization to a Łukasiewicz first-order logic Ł xx with [0,1]-valued identity. Models of Ł xx are suitable sets X of unit vectors in a Hilbert space H, and the identity degree of any two vectors u; v 2 X is their scalar product; functions and relations on X satisfy suitable continuity properties.Since this book is devoted to these genuine MV-algebraic and logical topics, its overlap with books on '-groups, with or witho...