the inequality \textbackslash{}Q . w\textbackslash{} less than or equal to \textbackslash{}Q\textbackslash{} - n holds provided that \textbackslash{}Q . u\textbackslash{} less than or equal to \textbackslash{}Q\textbackslash{} - n for some word u (depending on A). We give an algorithm to test whether a word is 2-collapsing. To this aim we associate to every word w a finite family of finitely generated subgroups in finitely generated free groups and prove that the property of being 2-collapsing reflects in the property that each of these subgroups has index at most 2 in the corresponding free group. We also find a similar characterization for the closely related class of so-called 2-synchronizing words. (C) 2003 Elsevier B.V. All rights reserved.
Поле | Значение |
Month | SEP 26 |
Note | 3rd Conference on WORDS, PALERMO, ITALY, SEP, 2001 |
Publisher | ELSEVIER SCIENCE BV |
Address | PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS |
Language | English |
Research-Areas | Computer Science |
Web-of-Science-Categories | Computer Science, Theory \& Methods |
ResearcherID-Numbers | Volkov, Mikhail/F-1407-2014 |
ORCID-Numbers | Volkov, Mikhail/0000-0002-9327-243X |
Number-of-Cited-References | 13 |
Usage-Count-Since-2013 | 1 |
Journal-ISO | Theor. Comput. Sci. |
Doc-Delivery-Number | 723RY |