Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extending the exact sequence of nonabelian $H^1$, using nonabelian $H^2$
  with coefficients in crossed modules   In this note, following Dedecker and Debremaeker, we extend the cohomology
exact sequence for nonabelian $H^1$, using nonabelian $H^2$ with coefficients
in crossed modules.

29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph