Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Theory of Deeply Inelastic Scattering   The nucleon structure functions probed in deep-inelastic scattering at large
virtualities form an important tool to test Quantum Chromdynamics (QCD) through
precision measurements of the strong coupling constant $\alpha_s(M_Z^2)$ and
the different parton distribution functions. The exact knowledge of these
quantities is also of importance for all precision measurements at hadron
colliders. During the last two decades very significant progress has been made
in performing precision calculations. We review the theoretical status reached
for both unpolarized and polarized lepton-hadron scattering based on
perturbative QCD.

11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn