Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Amenability criterions and critical probabilities in percolation   A new proof of a Theorem of Nagnibeda and Pak on critical probabilities is
given. The distinctive feature is to use a criterion of Folner which has been
largely (and inexplicably) forgotten.

18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th