Alfred Aho
Alfred Vaino Aho (born August 9, 1941) is a Canadian computer scientist best known for his work on programming languages, compilers, and related algorithms, and his textbooks on the art and science of computer programming.
Career
Aho received a B.A.Sc. in Engineering Physics from the University of Toronto and a Ph.D. in Electrical Engineering/Computer Science from Princeton University. He conducted research at Bell Labs from 1967 to 1991, and again from 1997 to 2002 as Vice President of the Computing Sciences Research Center. As of 2011 he holds the Lawrence Gussman Chair of Computer Science at Columbia University. He served as chair of the department from 1995 to 1997, and again in the spring of 2003.
In his PhD thesis Aho created indexed grammars and the nested-stack automaton as vehicles for extending the power of context-free languages, but retaining many of their decidability and closure properties. Indexed grammars have been used to model parallel rewriting systems, particularly in biological applications.