Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Model Theory and Groups   This is a largely expository paper about how groups arise or are of interest
in model theory. Included are the following topics: classifying groups
definable in specific structures or theories and the relation to algebraic
groups, groups definable in stable, simple and NIP theories, definable
compactifications of groups, definable Galois theory (including differential
Galois theory), connections with topological dynamics, model theory of the free
group.

30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex