An introduction to many valued and fuzzy logic : semantics algebras and derivation systems Review of classical propositional logic Review of classical first order logic Alternative semantics for truth values and truth functions : numeric Truth values and abstract algebras Three valued propositional logics : semantics Derivation systems for three valued propositional logic Three valued first order logics : semantics Derivation systems for three valued first order logics Alternative semantics for three valued systems The principle of charity reconsidered and a new problem of the fringe Fuzzy propositional logics : semantics Fuzzy algebras Derivation systems for fuzzy propositional logics Fuzzy first order logics : semantics Derivation systems for fuzzy first order logics Extensions of fuzziness Fuzzy membership functions