- #1
snesnerd
- 26
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Homework Statement
If [itex](X,d)[/itex] is a metric space. I want to show that the set of all open balls and [itex]\emptyset[/itex] form a base.
Homework Equations
The Attempt at a Solution
I know that we need to show that the union of all these sets (or balls) is the whole set. I feel like this is simple yet, I am unsure what to write so that I do not miss any important facts.