On Ponomarev-Systems
Bollettino della Unione matematica italiana, Série 8, 10B (2007) no. 2, pp. 455-467
Voir la notice de l'article provenant de la source Biblioteca Digitale Italiana di Matematica
Zbl MR
In this paper the relations of mappings and families of subsets are investigated in Ponomarev-systems, and the following results are obtained. (1) $f$ is a sequence-covering (resp. 1-sequence-covering) mapping iff $\mathcal{P}$ is a csf -network (resp. snf -network) of $X$ for a Ponomarev-system $(f, M, X, \mathcal{P})$; (2) $f$ is a sequence-covering (resp. 1-sequence-covering) mapping iff every $\mathcal{P}_n$ is a cs-cover (resp. wsn-cover) of$X$ for a Ponomarev-system $(f, M, X, \{\mathcal{P}_n \})$. As applications of these results, some relations between sequence-covering mappings and 1-sequence-covering mappings are discussed, and a question posed by S. Lin is answered.
Ge, Ying; Shou, Lin. On Ponomarev-Systems. Bollettino della Unione matematica italiana, Série 8, 10B (2007) no. 2, pp. 455-467. http://geodesic.mathdoc.fr/item/BUMI_2007_8_10B_2_a13/
@article{BUMI_2007_8_10B_2_a13,
author = {Ge, Ying and Shou, Lin},
title = {On {Ponomarev-Systems}},
journal = {Bollettino della Unione matematica italiana},
pages = {455--467},
year = {2007},
volume = {Ser. 8, 10B},
number = {2},
zbl = {1143.54003},
mrnumber = {2339454},
language = {en},
url = {http://geodesic.mathdoc.fr/item/BUMI_2007_8_10B_2_a13/}
}