Fixed and Stationary ω —Words and ω —Languages
Explicit representations of the ω-words that are fixed (resp., stationary) relative to a function h: A -→ A* are given. A procedure is provided for constructing a concise expression for the fixed (resp., stationary) ω -language of such an h. The equivalence problem for fixed (resp., stationary) ω-languages of functions h & k: A -→ A* is shown to be decidable. The fundamental tool for this latter procedure is the recently developed algorithm of K. Culik II & T. Harju for deciding the ω -sequence equivalence problem.
KeywordsLanguage Theory Cardinal Number Monogenic Function Free Monoids Concise Expression
Unable to display preview. Download preview PDF.
- T. Harju and M. Linna, On the periodicity of morphisms on free monoids, RAIRO Informatique Théorique (to appear).Google Scholar
- J.J. Pansiot, Decidability of periodicity for infinite words, RAIRO Informatique Théorique (to appear).Google Scholar
- A. Salomaa, Morphisms on free moniods and language theory, in: R.V. Book, ed., Formal Language Theory (Academic Press, New York, 1980).Google Scholar
- A. Salomaa, Jewels of Formal Language Theory (Computer Science Press, Rockville, MD, 1917.Google Scholar