in this paper, a new class of multifunctions, called generalized alpha (mu_{x};mu_{ y} )-continuous multifunctions, has been de ned and studied. some characterizations and severalproperties concerning generalized alpha (mu_{x};mu_{ y} )-continuous multifunctions are obtained. the re-lationships between generalized alpha (mu_{x};mu_{ y} )-continuous multifunctions and some known con-ce...

This paper is concerned with the existence of extreme solutions of the three-point boundary value problem for a class of second order functional differential equations. We introduce new concept of lower and upper solutions. By using the method of upper and lower solutions and monotone iterative technique, we obtain the existence of extreme solutions.

In this paper we use the method of upper and lower solutions to study multivalued Sturm{Liouville and periodic boundary value problems , with Caratheodory orientor eld. We prove two existence theorems. One when the orientor eld F (t; x; y) is convex{valued and the other when F (t; x; y) is nonconvex valued. Finally we show that the \convex" problem has extremal solutions in the order interval d...