Position Automaton Construction for Regular Expressions with Intersection

Positions and derivatives are two essential notions in the conversion methods from regular expressions to equivalent finite automata. Partial derivative based methods have recently been extended to regular expressions with intersection. In this paper, we present a position automaton construction for those expressions. This construction generalizes the notion of position making it compatible with intersection. The resulting automaton is homogeneous and has the partial derivative automaton as its quotient

derivatives of regular expressions and an application

In this paper, we propose a characterization of the structure of derivatives and prove several new properties of derivatives for regular expressions. The above work can be used to solve an issue in using Berry and Sethi's result, i.e., finding the unique representatives of derivatives. As an application, an improvement of Ilie and Yu's proof of the relation between the partial derivative and Glushkov automata is presented. © 2012 Springer-Verlag.In this paper, we propose a characterization of the structure of derivatives and prove several new properties of derivatives for regular expressions. The above work can be used to solve an issue in using Berry and Sethi's result, i.e., finding the unique representatives of derivatives. As an application, an improvement of Ilie and Yu's proof of the relation between the partial derivative and Glushkov automata is presented. © 2012 Springer-Verlag