Closure properties of subclasses of ω-regular languages under morphism and inverse morphism
Tetsuo Moriya · International Journal of Computer Mathematics · 1992
We study ω-languages by using morphism and inverse morphism. We investigate the closure properties of some subclasses of ω-regular languages under ε-free morphism and inverse morphism (for ε-free case and for arbitrary case). As one of the results, we have that the only Rω, the class of all ω-regular languages, is closed under both ε-free morphism and inverse (arbitrary) morphism.