Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The congruence subgroup problem   This is a short survey of the progress on the congruence subgroup problem
since the sixties when the first major results on the integral unimodular
groups appeared. It is aimed at the non-specialists and avoids technical
details.

14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th