Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On systems of rational difference equations and periodic tetrachotomies   We study the following system of two rational difference equations
x_n=({\beta}_k x_(n-k)+{\gamma}_k y_(n-k))/(A+\Sigma_(j=1)^l[B_j x_(n-j)
]+\Sigma_(j=1)^l[C_j y_(n-j) ]), n \in N, y_n=({\delta}_k x_(n-k)+\in_k
y_(n-k))/(q+\Sigma_(j=1)^l[D_j x_(n-j) ]+\Sigma_(j=1)^l[E_j y_(n-j) ]), n\in N,
with nonnegative parameters and nonnegative initial conditions. We assume that
B_j=C_j=D_j=E_j=0 for j=k, 2k, 3k, ...and establish the existence of periodic
tetrachotomy behavior which depends on a 2X2 matrix with entries {\beta}_k,
{\gamma}_k, {\delta}_k, and \in_k.

15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th