Two examples
Posted: Sat Mar 30, 2019 8:43 am
- Give an example of a descending sequence $(F_n)_{n\in\mathbb{N}}$ of non-empty closed subsets of metric space $(\mathbb{R}, |\cdot|)$, such that $\bigcap_{n=1}^{\infty}F_n=\varnothing$.
- Give an example of a descending sequence $(F_n)_{n\in\mathbb{N}}$ of non-empty closed subsets of metric space $(\mathbb{Q}, |\cdot|)$, such that ${\rm{diam}}(F_n)\xrightarrow{n\to+\infty} 0$ and $\bigcap_{n=1}^{\infty}F_n=\varnothing$.