Factor versus palindromic complexity of uniformly recurrent infinite words
نویسندگان
چکیده
We study the relation between the palindromic and factor complexity of infinite words. We show that for uniformly recurrent words one has P(n) + P(n + 1) ≤ ∆C(n) + 2, for all n ∈ N. For a large class of words it is a better estimate of the palindromic complexity in terms of the factor complexity then the one presented in [2]. We provide several examples of infinite words for which our estimate reaches its upper bound. In particular, we derive an explicit prescription for the palindromic complexity of infinite words coding r-interval exchange transformations. If the permutation π connected with the transformation is given by π(k) = r+1−k for all k, then there is exactly one palindrome of every even length, and exactly r palindromes of every odd length.
منابع مشابه
A connection between palindromic and factor complexity using return words
In this paper we prove that for any uniformly recurrent infinite word w, the following conditions are equivalent: (I) all complete returns to palindromes are palindromes; (II) P(n) + P(n+ 1) = C(n+ 1)− C(n) + 2 for all n, where P (resp. C) denotes the palindromic complexity (resp. factor complexity) function of w, which counts the number of distinct palindromic factors (resp. factors) of each l...
متن کاملOn Brlek-Reutenauer conjecture
Brlek and Reutenauer conjectured that any infinite word u with language closed under reversal satisfies the equality 2D(u) = ∑ +∞ n=0 Tu(n) in which D(u) denotes the defect of u and Tu(n) denotes Cu(n + 1) − Cu(n) + 2 − Pu(n + 1) − Pu(n), where Cu and Pu are the factor and palindromic complexity of u, respectively. Brlek and Reutenauer verified their conjecture for periodic infinite words. Usin...
متن کاملProof of the Brlek-Reutenauer conjecture
Brlek and Reutenauer conjectured that any infinite word u with language closed under reversal satisfies the equality 2D(u) = +∞ n=0 Tu(n) in which D(u) denotes the defect of u and Tu(n) denotes Cu(n + 1) − Cu(n) + 2 − Pu(n + 1) − Pu(n), where Cu and Pu are the factor and palindromic complexity of u, respectively. This conjecture was verified for periodic words by Brlek and Reutenauer themselves...
متن کاملInfinite words without palindrome
We show that there exists an uniformly recurrent infinite word whose set of factors is closed under reversal and which has only finitely many palindromic factors. 1 Notations For a finite word w = w1 · · ·wn, the reversal of w is the word w̃ = wn · · ·w1. This notation is extended to sets by setting F = {w̃ | w ∈ F} for any set F of finite words. A word w is a palindrome if w̃ = w. A set F of fini...
متن کاملCorrigendum: "On Brlek-Reutenauer conjecture"
Bašić (2012) in [1] pointed to a gap in the proof of Corollary 5.10 in Balková et al. (2011) [2] related to the Brlek–Reutenauer conjecture. In this corrigendum, we correct the proof and show that the corollary remains valid. © 2012 Elsevier B.V. All rights reserved. 1. Corrigendum Brlek and Reutenauer conjectured that any infinite word u with language closed under reversal satisfies the equali...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Theor. Comput. Sci.
دوره 380 شماره
صفحات -
تاریخ انتشار 2007