Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Actions of trees on semigroups, and an infinitary Gowers--Hales--Jewett
  Ramsey theorem
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex