Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mark sequences in digraphs   A k-digraph is an orientation of a multi-graph that is without loops and
contains at most k edges between any pair of distinct vertices. We obtain
necessary and sufficient conditions for a sequence of non-negative integers in
non-decreasing order to be a sequence of numbers, called marks (k-scores),
attached to vertices of a k-digraph. We characterize irreducible mark sequences
in k-digraphs and uniquely realizable mark sequences in 2-digraphs.

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The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph