Resumen de Boundary value problems involving upper and lower solutions in reverse order

Weibing Wang, Xuxin Yang, Jianhua Shen

• In this paper, we discuss the existence of extreme solutions of the boundary value problem for a class of first-order functional equations with a nonlinear boundary condition. In the presence of a lower solution a and an upper solution ß with ß=a, we establish existence results of extreme solutions by using the method of upper and lower solutions and a monotone iterative technique.