In page 15 of Lee's book "Introduction to Smooth Manifolds", there's a paragraph as follows:
We say a set $B\subset M$ is a regular coordinate ball if there is a smooth coordinate ball $B'\supset \bar B$ and a smooth coordinate map $\varphi:B'\to \Bbb R^n$ such that for some positive real numbers $r<r'$, $\varphi (B)=B_r(0),\quad\varphi(\bar B)=\bar B_r(0),\quad$ and $\varphi (B')=B_{r'}(0).$
If we change the above definition as follows:
We say a set $B\subset M$ is a regular coordinate ball if there is a smooth coordinate ball $B'\supset B$ and a smooth coordinate map $\varphi:B'\to \Bbb R^n$ such that for some positive real numbers $r<r'$, $\varphi (B)=B_r(0), \quad\varphi (B')=B_{r'}(0).$
Are they equivalent?
$$\varphi^{-1}:B_{r'}(0)\to B'$$ $$\varphi^{-1}(B_{r}(0))=B$$ Thus $\varphi^{-1}(\bar B_{r}(0))$ is compact, because every compact subset of a Hausdorff space is closed, so $\varphi^{-1}(\bar B_{r}(0))=\bar B$, then we have $B'\supset \bar B$ and $\varphi (\bar B)=\bar B_{r}(0)$.