Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The symplectic mapping class group of $\CC P^2 n{\bar{\CC P^2}}$ with
  $n\leq4$   In this paper we prove that the Torelli part of the symplectomorphism groups
of the $n$-point ($n\leq 4$) blow-ups of the projective plane is trivial.
Consequently, we determine the symplectic mapping class group. It is generated
by reflections on $K_{\omega}- $spherical class with zero $\omega$ area.

16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys