Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the X-rays of permutations   The X-ray of a permutation is defined as the sequence of antidiagonal sums in
the associated permutation matrix. X-rays of permutation are interesting in the
context of Discrete Tomography since many types of integral matrices can be
written as linear combinations of permutation matrices. This paper is an
invitation to the study of X-rays of permutations from a combinatorial point of
view. We present connections between these objects and nondecreasing
differences of permutations, zero-sum arrays, decomposable permutations, score
sequences of tournaments, queens' problems and rooks' problems.

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The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: nlin
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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: plasm-ph
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The categories of this paper are: math-ph
1
The categories of this paper are: cs