ABSTRACT
In this chapter we study multivalued problem with nonlinear boundary conditions in which the usual differential operator https://www.w3.org/1998/Math/MathML"> x ↦ x ' ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429218576/b5164108-1897-4637-a93d-46e387408a02/content/eq10595.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is substitued by the operator https://www.w3.org/1998/Math/MathML"> x ↦ ϕ x ' ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429218576/b5164108-1897-4637-a93d-46e387408a02/content/eq10596.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . We prove the existence of solutions and extremal solutions in the order interval delimited by the lower and upper solution. The boundary conditions considered by us contains, as a particular case, the Dirichlet, periodic, Nuemann and Sturm-Liouville conditions.
Keywords and Phrases: Upper solution, lower solution, order interval, extremal solutions, nonlinear boundary conditions
1991 AMS Subject Classification: 34B 15
