An introduction to symbolic dynamics and coding
An introduction to symbolic dynamics and coding
Introduction To Automata Theory, Languages, And Computation
Introduction To Automata Theory, Languages, And Computation
Ensembles reconnaissables de mots bi -infinis limite et déterminisme
Automata on Infinite Words, Ecole de Printemps d'Informatique Théorique,
On the hartmanis-stearns problem for a class of tag machines
SWAT '68 Proceedings of the 9th Annual Symposium on Switching and Automata Theory (swat 1968)
| Hi-index | 0.00 |
Let Σ be a finite alphabet, and let h : Σ* → Σ* be a morphism. Finite and infinite fixed points of morphisms -- i.e., those words w such that h(w) = w -- play an important role in formal language theory. Head characterized the finite fixed points of h, and later, Head and Lando characterized the one-sided infinite fixed points of h. Our paper has two main results. First, we complete the characterization of fixed points of morphisms by describing all two-sided infinite fixed points of h, for both the "pointed" and "unpointed" cases. Second, we completely characterize the solutions to the equation h(xy) = yx in finite words.