In this paper, we first introduce some types of set relations on the power set of n-dimensional Euclidean spaces which are proposed by Kuroiwa-Tanaka-Ha and Jahn-Ha. We also mension new types of cancellation laws of set relations. Second, we introduce a complete lattice-valued problem on the power set of n-dimensional Euclidean spaces proposed by Hamel et al. Applying nonlinear scalrizing technique in complete lattice, we present a new type of minimal element theorem and generalized Ekeland’s variational principle in complete lattice optimization problem.
AMS Subject Classification: 06B23, 06F30, 49J53, 58E17.