Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The general solutions of some nonlinear second order PDEs.I. Two
  independent variables, constant parameters   In the first part of planned series of papers the formal general solutions to
selection of 80 examples of different types of second order nonlinear PDEs in
two independent variables with constant parameters are given. The main goal
here is to show on examples the types of solvable PDEs and what their general
solutions look like. The solving strategy, used here, as a rule is the order
reduction. The order reduction method is implemented in Maple procedure, which
applicable to PDEs of different order with different number of independent
variables. Some of given PDEs are solved by order lifting to PDEs, which are
solvable by the subsequent order reduction.

29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con