Function defined near a point 

[(31, 86), (94, 121), (140, 179), (267, 298), (340, 373), (393, 442), (454, 483)]

Let $f: D \to \mathbb{R}$ be a real valued function from a subset $D$ of the set of real numbers $\mathbb{R}$.

We say that $f$ is defined near $a \in \mathbb{R}$ if there is some interval $I$ such that

  1. $a \in I$ and
  2. $f$ is defined on $I \setminus \{a\}$1,2, i.e. the domain $D$ of $f$ contains $I \setminus \{a\}$.

  1. https://hyunjongkimmath.github.io/mathbook/notation.basic.html#$\setminus$↩

  2. https://hyunjongkimmath.github.io/mathbook/notation.basic.html#$\{a\}$↩