Show that if $\displaystyle a,b$ $\displaystyle \in$$\displaystyle \Re$, and $\displaystyle a$$\displaystyle \neq$$\displaystyle b$, then there exist $\displaystyle \epsilon$-neighborhoods $\displaystyle U$ of $\displaystyle a$ and $\displaystyle V$ of $\displaystyle b$ such that $\displaystyle U$ $\displaystyle \cap$ $\displaystyle V$ = $\displaystyle \emptyset$