Professor Merrie Bergmann presents an accessible introduction to the subject of many-valued and fuzzy logic designed for use on undergraduate and graduate courses in non-classical logic. Bergmann discusses the philosophical issues that give rise to fuzzy logic - problems arising from vague language - and returns to those issues as logical systems are presented. For historical and pedagogical reasons, three-valued logical systems are presented as useful intermediate systems for studying the principles and theory behind fuzzy logic. The major fuzzy logical systems - Lukasiewicz, Gödel, and product logics - are then presented as generalisations of three-valued systems that successfully address the problems of vagueness. A clear presentation of technical concepts, this book includes exercises throughout the text that pose straightforward problems, that ask students to continue proofs begun in the text, and that engage students in the comparison of logical systems.

Accessible introduction explains the basic theories to the reader • Clear presentation allows the reader to get to grips with technical concepts • Includes algebras and axiomatics along with semantics and philosophical issues

Contents
Preface; 1. Introduction; 2. Review of classical propositional logic; 3. Review of classical first-order logic; 4. Alternative semantics for truth-values and truth-functions; 5. Three-valued propositional logics: semantics; 6. Derivation systems for three-valued propositional logic; 7. Three-valued first-order logics: semantics; 8. Derivation systems for three-valued first-order logics; 9. Alternative semantics for three-valued systems; 10. The principle of charity reconsidered and a new problem of the fringe; 11. Fuzzy propositional logics: semantics; 12. Fuzzy algebras; 13. Derivational systems for fuzzy propositional logics; 14. Fuzzy first-order logics: semantics; 15. Derivation systems for fuzzy first-order logics; 16. Extensions of fuzziness; 17. Fuzzy membership functions.