A survey of state vectors

The theory of Turing machines, which is basic to proving the various limitations of computers, is quite well known. The theory of finite state automata, the basic hardware models such as Moore machines, Mealy machines, and their generalizations, are similarly well known. Our purpose here is to survey basic work done between 1958 and 1975 on still another mathematical model for computer science, the state vector model. In this model there are many variables, each with its own current value, rather than a single state; this makes the model closer to what happens in a real computer.