Fuzzy Mathematics

In the mid-1960''s I had the pleasure of attending a talk by Lotfi Zadeh at which he presented some of his basic (and at the time, recent) work on fuzzy sets. Lotfi''s algebra of fuzzy subsets of a set struck me as very nice; in fact, as a graduate student in the mid-1950''s, I had suggested similar ideas about continuous-truth-valued propositional calculus (inffor "and", sup for "or") to my advis...