I am trying to prove something but my proofs requires me to make the step from saying that a function $f(x)$ is continuous at all points $x \in \mathbb{R} \implies f(x)$ is continuous over an interval $[x,x+\epsilon]$.
I know it may seem obvious and trivial but I just wanted a clarification on this.
Thanks!
(I know there is a similar question to this but it does not talk about when the function is continuous at every real)