Statement:
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 \(\cal V(x) \subseteq \cal B(x)\).
Howard_Rubin_Number: 426
Parameter(s): This form does not depend on parameters
This form's transferability is: Unknown
This form's negation transferability is: Negation Transferable
Article Citations:
Gutierres-2004: On first and second countable spaces and the axiom of choice
Book references
Note connections:
Note 159
Definitions for forms [0 AV], [8 AP] through [8 AS], [94 X], and Form 424 from Gutierres [2004].
Howard-Rubin Number | Statement | References |
---|---|---|
426 A | The conjunction of Form 76 (\(MC_\omega(\infty,\infty)\)) and Form 8 (\(C(\aleph_0,\infty)\)). |
Gutierres [2004]
|
426 B | The conjunction of Form 76 (\(MC_\omega(\infty, \infty)\)) and Form 31 (\(UT(\aleph_0,\aleph_0,\aleph_0)\)). |
Gutierres [2004]
|
426 C | The conjunction of Form 76 (\(MC_\omega(\infty,\infty)\)) and Form 32 (\(C(\aleph_0,\aleph_0)\)). |
Gutierres [2004]
|