JUCS - Journal of Universal Computer Science 5(9): 532-541, doi: 10.3217/jucs-005-09-0532
Decidable and Undecidable Problems of Primitive Words, Regular and Context-Free Languages
expand article infoSándor Horváth, Masami Ito§
‡ Department of Computer Science, L. Eötvös University, Hungary§ Department of Mathematics, Kyoto Sangyo University, Kyoto, Japan
Open Access
For any language L over an alphabet X, we define the root set, root(L) and the degree set, deg(L) as follows: (1) root(L) = where Q is the set of all primitive words over X, (2) deg(L) = . We deal with various decidability problems related to root and degree sets.
root sets, degree sets, regular languages, context-free languages, decidability problems