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Acta Mathematica Vietnamica

MAPPINGS IN ls-σ-FINITE PONOMAREV-SYSTEMS

NGUYEN VAN DUNG

Abstract

We introduce the notion of an ls-σ-finite Ponomarev-system (f,M,X,{Pλ,n}) to give a consistent method to construct an s-mapping (msss-mapping, mssc-mapping, cs-mapping) f with covering-properties from a locally separable metric space M onto a space X. As applications, we systematically get characterizations of s-images (msss-images, mssc-images, cs-images) with covering-properties of locally separable metric spaces.