WHICH TOPOLOGIES HAVE IMMEDIATE PREDECESSORS IN THE POSET OF HAUSDORFF TOPOLOGIES?

ALAS, Ofelia T.; TKACHENKO, Mikhail G.; WILSON, Richard G.

Artículos de revistas

Date

2009

Registration in:

HOUSTON JOURNAL OF MATHEMATICS, v.35, n.1, p.149-158, 2009

0362-1588

http://producao.usp.br/handle/BDPI/30611

http://apps.isiknowledge.com/InboundService.do?Func=Frame&product=WOS&action=retrieve&SrcApp=EndNote&UT=000265193200013&Init=Yes&SrcAuth=ResearchSoft&mode=FullRecord

http://repositorioslatinoamericanos.uchile.cl/handle/2250/1627250

Author

ALAS, Ofelia T.

TKACHENKO, Mikhail G.

WILSON, Richard G.

Institutions

Universidade de São Paulo (Brasil)

Abstract

We study which topology have an immediate predecessor in the poset of Sigma(2) of Hausdorff topologies on set X. We show that certain classes of H-closed topologies, do have predecessors. and we give examples of second countable H-closed topologies which are not upper Sigma(2.)