Title
A characterization of fine words over a finite alphabet
Abstract
To any infinite word t over a finite alphabet A we can associate two infinite words min(t) and max(t) such that any prefix of min(t) (resp. max(t)) is the lexicographically smallest (resp. greatest) amongst the factors of t of the same length. We say that an infinite word t over A is fine if there exists an infinite word s such that, for any lexicographic order, min(t)=as where a=min(A). In this paper, we characterize fine words; specifically, we prove that an infinite word t is fine if and only if t is either a strict episturmian word or a strict ''skew episturmian word''. This characterization generalizes a recent result of G. Pirillo, who proved that a fine word over a 2-letter alphabet is either an (aperiodic) Sturmian word, or an ultimately periodic (but not periodic) infinite word, all of whose factors are (finite) Sturmian.
Year
DOI
Venue
2008
10.1016/j.tcs.2007.10.029
Theoretical Computer Science
Keywords
Field
DocType
episturmian word,combinatorics on words,infinite word,fine word,skew episturmian word,lexicographic order,arnoux–rauzy sequence,2-letter alphabet,g. pirillo,skew word,finite alphabet,sturmian word,strict episturmian word,infinite words min,arnoux-rauzy sequence,skew word.
Combinatorics,Sturmian word,Existential quantification,Arithmetic,Prefix,Partial word,Skew,Lexicographical order,Aperiodic graph,Periodic graph (geometry),Mathematics
Journal
Volume
Issue
ISSN
391
1-2
Theoretical Computer Science
Citations 
PageRank 
References 
7
0.51
10
Authors
1
Name
Order
Citations
PageRank
Amy Glen11219.48