Design of Sequential Machines from Their Regular Expressions

Abstract

Procedures are given to convert any regular expression into a state diagram description and neural net realization of a machine that recognizes the regular set of sequences described by the given expression. It is established that any regular expression with a finite number of connectives describes a regular set of sequences that can be recognized by a finite state machine. All the procedures given are guaranteed to terminate in a finite number of steps, and a generalized computer program can be written to handle the entire conversion. An incidental result of the theory is the design of multiple output sequential machines. The potential usefulness of regular expressions and a long neglected form of a state diagram are demonstrated.