Q:

$\epsilon - \delta$ definition of continuity

I'm trying to give an $\epsilon - \delta$ definition for a function $f: \mathbb{R}_l \rightarrow \mathbb{R}$ to be continuous, where $\mathbb{R}_l$ denote $\mathbb{R}$ with lower limit topology. 
Here is my attempt: $f: \mathbb{R}_l \rightarrow \mathbb{R}$ is continuous at $p \in \mathbb{R}_l$ if given $\epsilon > 0$, there exists $\delta \geq 0$ such that if $\vert p - x \vert \leq \delta$, then $\vert f(p) - f(x) \vert < \epsilon$. It this correct? 

A:

What you provided was the usual definition of continuity. It should be:$$(\forall\varepsilon>0)(\exists\delta>0):p\leqslant x<p+\delta\implies\bigl\lvert f(x)-f(p)\bigr\rvert<\varepsilon.$$

