We consider the following system of Lyness-type difference equations: x 1 (n + 1) = (a k x k (n) + b k)/x k−1 (n − 1), x 2 (n + 1) = (a 1 x 1 (n) + b 1)/x k (n − 1), x i (n + 1) = (a i−1 x i−1 (n) + b i−1)/x i−2 (n − 1), i = 3,4,...,k, where a i , b i , i = 1,2,...,k, are positive constants, k ≥ 3 is an integer, and the initial values are positive real numbers. We study the existence of invariants, the boundedness, the persistence, and the periodicity of the positive solutions of this system.

No abstract

No abstract

No abstract

No abstract

We extend some results obtained in 1998 and 1999 by studying the periodicity of the solutions of the fuzzy difference equations xn+1=max{A/xn,A/xn−1,…,A/xn−k}, xn+1=max{A0/xn,A1/xn−1}, where k is a positive integer, A, Ai, i=0,1, are positive fuzzy numbers, and the initial values xi, i=−k,−k+1,…,0 (resp., i=−1,0) of the first (resp., second) equation are positive fuzzy numbers

In this paper we study the boundedness and the asymptotic behavior of the positive solutions of the system of difference equations

No abstract