Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the group generated by $\mathbf C$, $\mathbf{P}$ and $\mathbf T$:
  $\mathbf {I^2 = T^2 = P^2 = I T P= -1}$, with applications to pseudo-scalar
  mesons
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th