3 dense uncountable pairwise disjoint subsets of real line

general-topologyreal numbersreal-analysis

Can we find three dense uncountable pairwise disjoint subsets of $\mathbb{R}$? If so, what are these three sets?

I feel like it's not possible.

I was trying to counter it using Baire category and trying to construct such sets using the idea of construction of Cantor set (setting elements in trinary system). But I failed in both ways. I'm not even sure if answer would be affirmative or not.

Best Answer

Fix three disjoint dense subsets of $\mathbb{Q}$, call them $D_0, D_1$ and $D_2$.

Let $I_0=(0,1)\backslash \mathbb{Q}$, $I_1=(1,2)\backslash \mathbb{Q}$, $I_2=(2,3)\backslash \mathbb{Q}$ and set $J_k = I_k \cup D_k.$

Then, the sets $J_0, J_1$, and $J_2$ are disjoint, uncountable and dense.