A Symbolic Analysis of Relay and Switching Circuits is the title of a master's thesis written by computer science pioneer Claude E. Shannon while attending the Massachusetts Institute of Technology (MIT) in 1937,[1][2] and then published in 1938.
In his thesis, Shannon, a dual degree graduate of the University of Michigan, proved that Boolean algebra[3] could be used to simplify the arrangement of the relays that were the building blocks of the electromechanical automatic telephone exchanges of the day.
[4][5] The utilization of the binary properties of electrical switches to perform logic functions is the basic concept that underlies all electronic digital computer designs.
Shannon's thesis became the foundation of practical digital circuit design when it became widely known among the electrical engineering community during and after World War II.
At the time, the methods employed to design logic circuits (for example, contemporary Konrad Zuse's Z1) were ad hoc in nature and lacked the theoretical discipline that Shannon's paper supplied to later projects.