Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A counterexample to Las Vergnas' strong map conjecture on realizable
  oriented matroids
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th