Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the semi-dynamical reflection equation: solutions and structure
  matrices
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph