Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Relativistic wave equations of n-body systems of fermions and
  antifermions of various masses in quantum electrodynamics
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
18
The categories of this paper are: econ
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics