Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The generating function of two-stack sortable permutations by descents
  is real-rooted   The paper is withdrawn since the results are included in arXiv:math/0403364.

16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs