We consider the following boundary value problem: −Δny = F(k,y, Δy,…,Δn−1y), k ϵ Z[n − 1, N], Δiy(0) = 0, 0 ≤ i ≤ n − 2, Δpy(N + n - p) = 0, where n ≥ 2 and p is a fixed integer satisfying 0 ≤ p ≤ n − 1. Using a fixed-point theorem for operators on a cone, we shall yield the existence of at least three positive solutions.
