Max A. Zorn, 86, professor emeritus of mathematics at Indiana University, was the author of an algebraic formulation known as "Zorn's lemma." It is used in helping to explain the foundations of mathematics.
A resident of Bloomington, Ind., he died Tuesday in Bloomington Hospital in that city.
Professor Zorn, a native of Germany, fled from Nazism in 1934 and became a refugee scholar at Yale University. It was while there that he first created the formulation named for him. A lemma is defined as a subsidiary proposition used in proving some other proposition in mathematics.