Open ball
Set
| context | $\langle d,X\rangle$ … metric space |
| context | $a\in X$ |
| definiendum | $B_a:\mathbb R_+^*\to \mathcal P(X)$ |
| definiendum | $B_a(r):= \{x\ |\ d(x,a)<r \}$ |
Discussion
Reference
Wikipedia: Ball (Mathematics)
Parents
Context
| context | $\langle d,X\rangle$ … metric space |
| context | $a\in X$ |
| definiendum | $B_a:\mathbb R_+^*\to \mathcal P(X)$ |
| definiendum | $B_a(r):= \{x\ |\ d(x,a)<r \}$ |
Wikipedia: Ball (Mathematics)
