A generalization of the method of upper and lower solutions for discontinuous first order problems with nonlinear boundary conditions

摘要

In this paper we prove the existence of extremal solutions for a discontinuous BVP between a lower and an upper solution which may be discontinuous in a finite set of points. Furthermore we present a monotone method with which we can explicitly construct a pair of sequences that converge to the extremal solutions, despite the discontinuities of the right hand side of the equation.