Regular expression star-freeness is PSPACE-complete
László Bernátsky 1 2
It is proved that the problem of deciding if a regular expression denotes a star-free language is PSPACE -complete. The paper also includes a new proof of the PSPACE -completeness of the finite automaton aperiodicity problem.
1 Department of Computer Science, Attila József University, 6720 Szeged, Hungary, E-mail: firstname.lastname@example.org
2 Supported in part by grant no. T7383 of the National Foundation of Scientific Research of Hungary