Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Double Danielewski Surfaces and the Cancellation Problem   We study a two-dimensional family of affine surfaces which are
counter-examples to the Cancellation Problem. We describe the Makar-Limanov
invariant of these surfaces, determine their isomorphism classes and
characterize the automorphisms of these surfaces.

30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph