Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Existence and Multiplicity Results for Systems of Singular Boundary
  Value Problems
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat