Closed disc
= Closed disc
= Closed disk
{synonym}
A closed $n$-disc is a space homeomorphic to $D^n=\{x\in\mathbb R^n:|x|\leq1\}$; its boundary is the sphere $S^{n-1}$.
= Closed disc
= Closed disk
{synonym}
A closed $n$-disc is a space homeomorphic to $D^n=\{x\in\mathbb R^n:|x|\leq1\}$; its boundary is the sphere $S^{n-1}$.