Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Periodic solutions of a system of nonlinear difference equations with
  periodic coefficients   In this paper it is dealt with the following system of difference equations
  x_{n+1}=((a_{n})/(x_{n}))+((b_{n})/(y_{n})),
y_{n+1}=((c_{n})/(x_{n}))+((d_{n})/(y_{n})), n in N_0,
  where the initial values x_0,y_0 are positive real numbers and the
coefficients (a_{n})_{n>=0}, (b_{n})_{n>=0}, (c_{n})_{n>=0}, (d_{n})_{n>=0} are
two-periodic sequences with positive terms. The system is an extention of a
system that every positive solution is two-periodic or converges to its a
two-periodic solution. Here, the long-term behavior of posistive solutions of
the system is examined by using a new method to solve the system.

0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin