期刊名称：International Journal of Mathematics and Mathematical Sciences
印刷版ISSN：0161-1712
电子版ISSN：1687-0425
出版年度：2008
卷号：2008
DOI：10.1155/2008/527106
出版社：Hindawi Publishing Corporation
摘要：We obtain new characterizations of open maps in terms of closures, of closed maps in terms of interiors, and of continuous maps in terms of interiors. Further open (closed) onto maps
𝑓∶𝑋→𝑌 are described in terms of images under 𝑓 of certain closed (open) sets in 𝑋. Continuity of (onto) maps is also characterized in terms of saturated sets.
