Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The 21 reducible polars of Klein's quartic   We describe the singularities and related properties of the arrangement of 21
reducible polars of Klein's quartic, containing Klein's well-known arrangement
of $21$ lines.

18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom