Research on Transforming FA into RE: Cycles-Broken Method

A Finite Automata (FA) and Regular Expression (RE) are the theoretical principle of the lexical analysis of the compiling technique, and they are equivalent each other. This paper analyzes the basic substitution rules and the general steps of the transforming from FA into RE, and explores a new idea: cycle-broken method. On the basis of it, we add two new substitution rules. The rules extend three original rules to five rules, and simplify the transforming FA into RE. Finally, we have illustrated the application of cycles-broken method by an example.