Variational Principles in Fang Uniform Spaces

Abstract

The vectorial Zhu-Li Variational Principle (ZLVP) in Fang uniform spaces is in the logical segment between the Brezis-Browder ordering principle (BB) and Ekeland's Variational Principle (EVP); hence, it is equivalent with both BB and EVP. In particular, the conclusion is applicable to Hamel's Variational Principle (HVP). Finally, a proof of [HVP equivalent with EVP] is provided, by means of a direct approach.