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Georgian Mathematical Journal 13 (2006), No. 2, 291--296 Copyright Heldermann Verlag 2006 A Positive Answer to Velichko's Question Jinjin Li Dept. of Mathematics, Zhangzhou Teachers' College, Zhangzhou, Fujian 363000, P. R. China jinjinli@fjzs.edu.c Zhaowen Li Dept. of Mathematics, Changsha University of Electric Power, Changsha, Hunan 410077, P. R. China We give a positive answer to Velichko's question in which the quotient and s-map is replaced by a sequence-covering and cs-map. In addition, let X have a star-countable k-network, then X is a sequence-covering and cs-image of a locally separable metric space if and only if X is a sequence-covering and cs-image of a metric space. Keywords: Sequence-covering maps, cs-mappings, cs-networks, k-networks, compact-countable covers, star-countable collections, cosmic spaces, aleph-0-spaces. MSC: 54E99, 54C10; 54D55 [ Fulltext-pdf (175 KB)] for subscribers only. |