Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On H-closed paratopological groups   A Hausdorff paratopological group G is H-closed if G is closed in each
Hausdorff paratopological group containing G. We obtain criteria of
H-closedness for some classes of abelian paratopological groups. In particular,
for topological groups.

34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat