Existence theorems for a system of difference equations with (n,p)-type conditions

摘要

We offer criteria for the existence of single and double solutions of fixed signs for the following system of boundary value problemswhere n⩾2, N⩾n−1, 1⩽pi⩽n−1, 1⩽i⩽m and the nonlinear terms qi's can be `positive' or `nonpositive'.