query: Why is the following space not first countable?
positive_passages.docid: 23837
positive_passages.text: Why is $\mathbb{R}/{\sim}$ not first countable at $[0]$, where $x \sim y \Leftrightarrow x = y\text{ or }x,y \in \mathbb{Z}$?
negative_passages.docid: 81999
negative_passages.text: What is this quotient space?
negative_passages.docid: 147136
negative_passages.text: Subset of a countable set is itself countable
negative_passages.docid: 157812
negative_passages.text: what is the [count=\i] in \foreach for?
negative_passages.docid: 87983
negative_passages.text: Examples of Separable Spaces that are not Second-Countable
negative_passages.docid: 97737
negative_passages.text: Why does doublespacing using setspace have errors when used in a minimal documentclass?
negative_passages.docid: 71489
negative_passages.text: Countable product of Polish spaces
negative_passages.docid: 115851
negative_passages.text: Why is this quotient space not Hausdorff?
negative_passages.docid: 36184
negative_passages.text: Countability of disjoint intervals
negative_passages.docid: 45111
negative_passages.text: Number of Subspaces that contains other Space
negative_passages.docid: 148507
negative_passages.text: Why an open set in $R^n$ might not be written as countable union of disjoint open intervals?
negative_passages.docid: 80414
negative_passages.text: Countable Product of Sequentially Compact spaces is Sequentially Compact
negative_passages.docid: 128437
negative_passages.text: How to prove that a finite set is countable
negative_passages.docid: 118595
negative_passages.text: Proving that a set is countable by finding a bijection
negative_passages.docid: 143003
negative_passages.text: $\bigcup \emptyset$ is defined but $\bigcap \emptyset$ is not. Why?
negative_passages.docid: 99599
negative_passages.text: Uncountable and countable
negative_passages.docid: 122048
negative_passages.text: why is the set of all binary sequences not countable?