Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Persistency of excitation for uniform convergence in nonlinear control
  systems
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int