Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The Newtonian limit of fourth-order gravity   The weak-field slow-motion limit of fourth-order gravity will be discussed.

11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph