Frechet-Urysohn space;
alpha(4)-space;
almost disjoint family;
convergent sequence;
D O I:
10.1016/S0166-8641(00)90096-8
中图分类号:
O29 [应用数学];
学科分类号:
070104 ;
摘要:
We shall construct in ZFC two Frechet-Urysohn alpha(4)-spaces, the product of which is alpha(4), but fails to be Frechet-Urysohn. This answers Nogura's question from 1985. (C) 2000 Elsevier Science B.V. All rights reserved.