Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Positively expansive homeomorphisms of compact spaces   We give a new and elementary proof showing that a homeomorphism of a compact
metric space is positively expansive if and only if the space is finite.

5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
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
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol