GENERALIZED UNIVERSAL THEOREM AND ALEKSANDROVE ISOMETRIC EXTENSION PROBLEM

Abstract

In this paper, Figiel's lemma that concerns the isometric embedding from a Banach space X into the continuous space C(L) are extended. That is a form of extension of universal theorem. Besides we obtain some isometric extending mappings which satisfy Aleksandrov's, i.e., some mapping that preserve one distance can be extend to isometry in whole space.