Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A new proof of a theorem of Ivanov and Schupp   The object of this note is to give a very short proof of the following
theorem of Ivanov and Schupp. Let H be a finitely generated subgroup of a free
group F and the index [F:H] infinite. Then there exists a nontrivial normal
subgroup N of F such that N cap H = {1}.

5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th