Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A characteristic-free proof of a basic result on D-modules   Let k be a field, let R be a ring of polynomials in a finite number of
variables over k, let D be the ring of k-linear differential operators of R and
let f be a non-zero element of R. It is well-known that R_f, with its natural
D-module structure, has finite length in the category of D-modules. We give a
characteristic-free proof of this fact. To the best of our knowledge this is
the first characteristic-free proof.

12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph