Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Permutation Complexity and the Letter Doubling Map   Given a countable set X (usually taken to be N or Z), an infinite permutation
$\pi$ of X is a linear ordering $<_\pi$ of X. This paper investigates the
combinatorial complexity of infinite permutations on N associated with the
image of uniformly recurrent aperiodic binary words under the letter doubling
map. An upper bound for the complexity is found for general words, and a
formula for the complexity is established for the Sturmian words and the
Thue-Morse word.

25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
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The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: stat