Fuzzy Sets, Logics and Reasoning about Knowledge reports recent results concerning the genuinely logical aspects of fuzzy sets in relation to algebraic considerations, knowledge representation and commonsense reasoning. It takes a state-of-the-art look at multiple-valued and fuzzy set-based logics, in an artificial intelligence perspective. The papers, all of which are written by leading contributors in their respective fields, are grouped into four sections. The first section presents a panorama of many-valued logics in connection with fuzzy sets. The second explores algebraic foundations, with an emphasis on MV algebras. The third is devoted to approximate reasoning methods and similarity-based reasoning. The fourth explores connections between fuzzy knowledge representation, especially possibilistic logic and prioritized knowledge bases. Readership: Scholars and graduate students in logic, algebra, knowledge representation, and formal aspects of artificial intelligence.

Introduction : Bridging the gap between multiple-valued logics, fuzzy logic, uncertain reasoning and reasoning about knowledge / Didier Dubois, Henri Prade and Erich Peter Klement — The Poincarâe paradox and non-classical logics / Ulrich Hèohle — Propositional fuzzy logics based on Frank t-norms : a comparison / Erich Peter Klement and Mirko Navara — A resolution-based axiomatisation of 'bold' propositional fuzzy logic / Stephan Lehmke — How to make your logic fuzzy : fibred semantics and the weaving of logics / Dov M. Gabbay — Introducing grade to some metalogical notions / Mihir K. Chakraborty and Sanjukta Basu — Closure operators, fuzzy logic and constraints / Giangiacomo Gerla — Ulam game, the logic of MaxSat, and many-valued partitions / Daniele Mundici — A many-valued generalisation of the ultrapower construction / Costas A. Drossos — Gabriel filters and the spectrum of an MV-algebra / Panagis Karazeris — Conditional states in finite-valued logics / Antonio Di Nola, George Georgescu and Ada Lettieri — Conditioning on MV-algebras and additive measures--further results / Siegfried Weber — Toward adequacy conditions for inference schemata in approximate reasoning : the case of the rule of syllogism / Siegfried Gottwald — Formal theories in fuzzy logic / Vilâem Novâak — A note on fuzzy inference as deduction / Lluâis Godo and Petr Hâajek — The role of similarity in fuzzy reasoning / Frank Klawonn — T-indistinguishability operators and approximate reasoning via CRI / Dionis Boixander and Joan Jacas — About similarity-based logical systems / Francesco Esteva, Pere Garcia and Lluâis Godo — On similarity-based fuzzy clusterings / Helmut Thiele — Informational representability : abstract models versus concrete models / Stâephane Demri and Ewa Or±owska — From possibilistic information to Kleene's strong multi-valued logics / Gert De Cooman — A roadmap of qualitative independence / D. Dubois ... et al. — Truth functionality and measure-based logics / Luca Boldrin and Claudio Sossai — Logic programs with context-dependent preferences / Gerhard Brewka — An overview of inconsistency-tolerant inferences in prioritized knowledge bases / Salem Benferhat, Didier Dubois and Henri Prade.