Alonzo Church was an American mathematician and logician who provided significant innovations in number theoryand decision theory, the foundation of computerprogramming. His most important contributions focus on the degrees of decidabilityand solvabilityin logic and mathematics.

Church was born in Washington, D.C., on June 14, 1903, to Samuel Robbins Church and Mildred Hannah Letterman Church. He took his undergraduate degree from Princeton University in 1924. On August 25, 1925, he married Mary Julia Kuczinski. They had three children: Alonzo, Mary Ann, and Mildred Warner. Church completed his Ph.D. in mathematics at Princeton in 1927. After receiving his doctorate, he was a fellow at Harvard from 1927 to 1928. He studied in Europe from 1928 to 1929 at the University of Göttingen, a prestigious center for the study of mathematics and physics. He taught mathematics and philosophy at Princeton from 1929 to 1968. Among his Ph.D. students at Princeton was the British mathematician Alan Turing, who was...