We have the following indirect implication of form equivalence classes:
| Implication | Reference |
|---|---|
| 426 \(\Rightarrow\) 8 |
On first and second countable spaces and the axiom of choice, Gutierres, G 2004, Topology and its Applications. |
| 8 \(\Rightarrow\) 361 | Zermelo's Axiom of Choice, Moore, 1982, page 325 |
| 361 \(\Rightarrow\) 362 | Zermelo's Axiom of Choice, Moore, 1982, page 325 |
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement |
|---|---|
| 426: | If \((X,\cal T) \) is a first countable topological space and \((\cal B(x))_{x\in X}\) is a family such that for all \(x \in X\), \(\cal B(x)\) is a local base at \(x\), then there is a family \(( \cal V(x))_{x\in X}\) such that for every \(x \in X\), \(\cal V(x)\) is a countable local base at \(x\) and \(\cal V(x) \subseteq \cal B(x)\). |
| 8: | \(C(\aleph_{0},\infty)\): |
| 361: | In \(\Bbb R\), the union of a denumerable number of analytic sets is analytic. G. Moore [1982], pp 181 and 325. |
| 362: | In \(\Bbb R\), every Borel set is analytic. G. Moore [1982], pp 181 and 325. |
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