A small hierarchy of languages consisting of non-primitive words
Pál Dömösi, Géza Horváth, Masami Itō · Publicationes Mathematicae Debrecen · 2004
Context-free languages consisting of non-primitive words have been characterized by M. Ito and M. Katsura in 1988.In this paper we show that the same type of characterization can be given for linear, respectively, regular languages consisting of non-primitive words.The observation completes our knowledge on the structure of different languages of non-primitive words.