Three positive fixed points of nonlinear ordered Banach spaces
We generalize the fixed-point theorem of Leggett-Williams, which is a theorem giving conditions that imply the existence of three fixed points of an operator defined on a cone in a Banach space. We then show how to apply our theorem to prove the existence of three positive solutions to a second-order discrete boundary value problem. (C) 2001 Elsevier Science Ltd. All rights reserved.
fixed-point theorems positive solutions boundary value problems difference equations