True or false:
If $E$ and $F$ are dense uncountable sets in $\mathbb R$, then $E\cap F$ is dense in $\mathbb R$.
I believe this is false. Consider two sets. The first being the non-negative rationals together with the negative irrationals. The second being the non-positive rationals together with the positive irrationals. Then each set is dense in $\mathbb{R}$ but their intersection is the singleton $0$.
Please critique my attempt to disprove this statement.
Your proof is absolutely correct.