A System of n , p.Boundary Value Problems with i i PositiverNonpositive Nonlinearities

We consider the system of boundary value problems u ini. t. qfi t,u1 t.,u2 t., . . . ,um t..s0, tgw0, 1x u ij. 0. s0su ipi. 1., 0FjFniy2 is1, 2, . . . , m, where niG2, 1FpiFniy1, 1FiFm. Several criteria are offered for the existence of single and twin solutions of the system that are of fixed signs