Ekeland ' S Principle in F - Type Spaces 3
نویسندگان
چکیده
We shall show that a recent version of Ekeland's principle in F-type topological spaces due to Fang from 1996 is implied by the Brezis-Browder principle on ordered sets. We give a series of equivalent formulations of Ekeland's principle in F-type topo-logical spaces, i.e. Penot's ower petal theorem, Takahashi's minimization principle and two theorems due to Oettli and Th era and show the equivalence of these to the version of Caristi's xed point theorem given by Fang.
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