| Title: | Functions that map cozerosets to cozerosets (English) | 
| Author: | Larson, Suzanne | 
| Language: | English | 
| Journal: | Commentationes Mathematicae Universitatis Carolinae | 
| ISSN: | 0010-2628 (print) | 
| ISSN: | 1213-7243 (online) | 
| Volume: | 48 | 
| Issue: | 3 | 
| Year: | 2007 | 
| Pages: | 507-521 | 
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| Category: | math | 
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| Summary: | A function $f$ mapping the topological space $X$ to the space $Y$ is called a {\it z-open\/} function if for every cozeroset neighborhood $H$ of a zeroset $Z$ in $X$, the image $f(H)$ is a neighborhood of $\operatorname{cl}_Y(f(Z))$ in $Y$. We say $f$ has the {\it z-separation property\/} if whenever $U$, $V$ are cozerosets and $Z$ is a zeroset of $X$ such that $U\subseteq Z\subseteq V$, there is a zeroset $Z'$ of $Y$ such that $f(U)\subseteq Z'\subseteq f(V)$. A  surjective function is z-open if and only if it maps cozerosets to cozerosets and has the z-separation property. We investigate z-open functions and other functions that map cozerosets to cozerosets. We show that if $f$ is a continuous z-open function, then the Stone extension of $f$ is an open function. This is used to show several properties of topological spaces related to F-spaces are preserved under continuous z-open functions. (English) | 
| Keyword: | open function | 
| Keyword: | cozeroset preserving function | 
| Keyword: | z-open function | 
| Keyword: | F-space | 
| Keyword: | SV space | 
| Keyword: | finite rank | 
| MSC: | 54C10 | 
| MSC: | 54C30 | 
| MSC: | 54C45 | 
| MSC: | 54G05 | 
| idZBL: | Zbl 1199.54099 | 
| idMR: | MR2374130 | 
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| Date available: | 2009-05-05T17:04:21Z | 
| Last updated: | 2012-05-01 | 
| Stable URL: | http://hdl.handle.net/10338.dmlcz/119675 | 
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