Stephen H. Schanuel (14 July 1933 – 21 July 2014) was an American mathematician working in the fields of abstract algebra and category theory, number theory, and measure theory.
[1][2] While he was a graduate student at University of Chicago, he discovered Schanuel's lemma, an essential lemma in homological algebra.
[2] Schanuel received his Ph.D. in mathematics from Columbia University in 1963, under the supervision of Serge Lang.
[2] Shortly thereafter he stated a conjecture in the field of transcendental number theory, which remains an important open problem to this day.
[2] Schanuel was a professor emeritus of mathematics at University at Buffalo.