Stephen Kleene

Stephen Cole Kleene (Hartford, Connecticut; January 5, 1909-Madison, Wisconsin; January 25, 1994) was an American logician and mathematician. He introduced the Kleene Closure operation, denoted by the symbol V*.

Biography

Kleene was born in Hartford, Connecticut, United States. He received his bachelor of arts degree from Amherts College in 1930. From 1930 to 1935 he was a graduate student and research assistant at Princeton University, where he received his doctorate in mathematics in 1934, supervised by Alonzo Church, for a thesis titled A Theory of Positive Integers in Formal Logic. In 1935 he joined the UW-Madison mathematics department as an instructor. He became a teaching assistant in 1937.

From 1939 to 1940 he was a visiting scholar at Princeton at the Institute for Advanced Study, where he founded the theory of recursive functions, an area of interest that would be investigated by him throughout his life. In 1941 he returned to Amherst as an associate professor of mathematics.

During World War II, Kleene was a Lieutenant Commander in the United States Navy. Additionally, he was a navigation instructor at the US Naval Reserve's Midshipmen's School in New York, and later a project director at the US Naval Research Laboratory in Washington, D.C.

In 1946 he returned to Wisconsin, becoming a professor in 1948. There he was chair of Mathematics and Computer Science in 1962 and 1963, and dean of the College of Letters and Sciences from 1969 to 1974. In 1964 he was called professor of Mathematics « "Cyrus C. MacDuffee." He retired in 1979.

An avid mountain climber, Kleene had a strong interest in nature and the environment, and participated in many environmental conservation causes. He led several professional organizations, serving as president of the Association of Symbolic Logic from 1956 to 1958. In 1961 he was president of the International Union of the History and the Philosophy of Science. He died in Madison, Wisconsin.