Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dual Structures in Non-Commutative Differential Algebras   The non-commutative algebraic analog of the moduli of vector and covector
fields is built. The structure of moduli of derivations of non-commutative
algebras are studied. The canonical coupling is introduced and the conditions
for appropriate moduli to be reflexive are obtained.

24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio