Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Generic properties of 2-step nilpotent Lie algebras and torsion-free
  groups
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph