J. 1979, On fuzzy logic I: Many-valued rules of inference, Zeitschr. f. math. Logik und Grundlagen d. Math., 25, 45–52. Covers proof theory of many-valued logics as well, in the tradition of Hájek. External links IEEE Computer Society's Technical Committee on Multiple-Valued Logic Resources for Many-Valued Logic by Reiner Hähnle, Chalmers University Many-valued Logics W3 Server (archived) Carlos Caleiro, Walter Carnielli, Marcelo E. Coniglio and João Marcos, Two's company: "The humbug of many logical values" in