John C.Mithcell is professor of Computer Science at Stanford University.he has been a featured speaker at intermational conferences;has led research projects on a variety of topics.including programming lagnuage design and analysis,computer security ,and applications of mathematical logic to computer science;and has writen more than 100 research articles.Professor Mitchell was s member of the programming language subcommittee of the ACM/IEEE Curriculum 2001 standardization effort and the 202 Program Chair of the ACM Principles of Programming Languages conference.