Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A proof of approximate controllability of the 3D Navier-Stokes system
  via a linear test
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci