Combinatorics on words
Taking a point of view from combinatorics on words has helped to obtain several important theorems in Diophantine approximation, some of which are discussed in the present book. In this appendix, we gather various results, some are classical, others less well known. Standard textbooks on combinatorics on words include [46, 310, 450].
Let be a finite or infinite set. A finite word W on the alphabet is either the empty word ε, or a finite block of elements from . The set of all finite words on is ...