Sy Friedman
Sy-David Friedman (born May 23, 1953 in Chicago) is an American and Austrian mathematician and a (retired) professor of mathematics at the University of Vienna and the former director of the Kurt Gödel Research Center for Mathematical Logic. His main research interest lies in mathematical logic, in particular in set theory and recursion theory. Friedman is the brother of Ilene Friedman and the brother of mathematician Harvey Friedman. Biography. He studied at Northwestern University and, from 1970, at the Massachusetts Institute of Technology. He received his Ph.D. in 1976 from MIT (his thesis "Recursion on Inadmissible Ordinals