===== Countable base for a topology =====
==== Set ====
| @#55CCEE: context     | @#55CCEE: $\langle X,T\rangle$ ... topological space |
| @#FFBB00: definiendum | @#FFBB00: $B\in$ it |
| @#55EE55: postulate   | @#55EE55: $B$ ... base |
| @#55EE55: postulate   | @#55EE55: $B$ ... countable |

==== Discussion ====
==== Parents ====
=== Context ===
[[Topological space]]
=== Subset of ===
[[Base for a topology]], [[Countable set]]