... pp. 588–611, 2010.17 D. J. Guo and V. Lakshmikantham, Nonlinear Problems in Abstract Cones, vol. 5 of Notes and Reports in Mathematics in Science and Engineering, Academic Press, Boston, Mass, ... χuμt for t ∈ 0, 1. We assert that χ ≥ 1. Suppose on the contrary that 0 < χ<1.Since Tλis a θ-concave increasing operator and for given u ∈◦P, Tλu is strictly increasing in λ,we ... attention. For instance,Ma 6, 7 and L. Kong and Q. Kong 8–10 studied some second-order multipointnonhomogeneous BVPs. In particular, L. Kong and Q. Kong 10 considered the followingsecond-order...