Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Free convex sets defined by rational expressions have LMI
  representations
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int