Is there a way to form a sequence of intervals $C_i \subset \mathbb{R} $ such that they cover all the rational numbers in $(0,1)$ in a way that $$C_n \subset Int(C_{n+1}),$$ where $C_i$ is closed.
Note: It is the standard topology.
Is there a way to form a sequence of intervals $C_i \subset \mathbb{R} $ such that they cover all the rational numbers in $(0,1)$ in a way that $$C_n \subset Int(C_{n+1}),$$ where $C_i$ is closed.
Note: It is the standard topology.
Now you just need a set of nested closed intervals with union $(0,1)$. You can just have $ C_i=[\frac 1{i+3},1-\frac 1{i+3}]$ for example. Then to form a partition of the rationals just take the rationals in $C_{i+1}\setminus C_i$