Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The AB equations and the $\bar\partial$-dressing method in
  semi-characteristic coordinates
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn