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Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika, 2017, Number 5, Pages 48–51
(Mi vmumm95)
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This article is cited in 3 scientific papers (total in 3 papers)
Short notes
The weak form of normality
A. P. Kombarov Lomonosov Moscow State University, Faculty of Mechanics and Mathematics
Abstract:
A topological space is said to be paranormal if every countable discrete collection of closed sets $\{D_n: n<\omega\}$ can be expanded to a locally finite collection of open sets $\{U_n: n<\omega\}$, i.e., $D_n\subset U_n$ and $D_m\cap U_n\not=\emptyset$ if and only if $D_m=D_n$. It is proved that if $\mathcal{F}:$ Comp $ \to$ Comp is a normal functor of degree $\geq 3$ and the compact space ${\mathcal{F}}(X)$ is hereditarily paranormal, then the compact space $X$ is metrizable.
Key words:
normal functor, compact space, hereditarily paranormality, metrizability.
Received: 20.04.2016
Citation:
A. P. Kombarov, “The weak form of normality”, Vestnik Moskov. Univ. Ser. 1. Mat. Mekh., 2017, no. 5, 48–51; Moscow University Mathematics Bulletin, 72:5 (2017), 203–205
Linking options:
https://www.mathnet.ru/eng/vmumm95 https://www.mathnet.ru/eng/vmumm/y2017/i5/p48
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