Siegfried Johannes Gottwald, born on March 30, 1943 in Limbach, Saxony and died September 20, 2015.
Siegfried was a German mathematician, logician and historian of science.
From 1961 to 1966, Siegfried studied mathematics at the University of Leipzig, where he was awarded his doctor title in 1969 and his habilitation in 1977.
He was tenured professor of non-classical and mathematical logic at University of Leipzig where he taught from 1972 to his retirement in 2008.
Siegfried main research areas are fuzzy sets and fuzzy methodologies, many-valued logic and history of mathematics.
He published several books on many-valued logic, fuzzy sets and their applications, co-authored a textbook on calculus and a reader in the history of logic.
Siegfried also contributed to the German biographical dictionary of mathematicians, Lexikon beruhmter Mathematiker.
Professor Siegfried Gottwald was Vice-Dean of the Faculty of Social Sciences and Philosophy at University of Leipzig for several years. He was married with three children.
Siegfried died at age 72 on September 20, 2015.