We show that every solution of the following system of difference equations xn 1 1 xn 2 / xn 2 ? 1 , x 2 n 1 x 3 n / xn 3 ? 1 , . . . , xn k 1 xn 1 / xn 1 ? 1 as well as of the system xn 1 1 xn k / xn k ? 1 , xn 2 ...