Asymptotic behavior and oscillation of delay partial difference equations with positive and negative coefficients

We obtain sufficient conditions for the oscillation of all solutions of the linear partial difference equations with positive and negative coefficients of the form A_m-1,n + A_m,n-1 -A_mn + pA_{m+k n+l} - qA_{m+k′ n+l′} = 0, and A_m-l,n + A_m,n-1 - A_mh + p_mn A_{m+k n+l} - q _mnA _{m+k′ n+l′}=0, where m, n = 0,1,..., and k, k′, l′, l are nonnegative integers p, q ∈ (0, ∞), and coefficients {q_mn} and {p_mn} are sequences of nonnegative real numbers. In this paper A_{m n} = A_m,n.