کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4660664 1344379 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
What is a first countable space?
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات هندسه و توپولوژی
پیش نمایش صفحه اول مقاله
What is a first countable space?
چکیده انگلیسی

The definition of first countable space is standard and its meaning is very clear. But is that the case in the absence of the Axiom of Choice? The answer is negative because there are at least three choice-free versions of first countability. And, most likely, the usual definition does not correspond to what we want to be a first countable space. The three definitions as well as other characterizations of first countability are presented and it is discussed under which set-theoretic conditions they remain equivalent.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Topology and its Applications - Volume 153, Issue 18, 1 December 2006, Pages 3420-3429