Definition:Neighborhood of Infinity (Complex Analysis)

Definition
A neighborhood of $\infty$ in $\C$ is a subset of the set of complex numbers $\C$ wich contains a set of the form $\{z \in \C : |z| > r\}$ for some $r\in\R$.

That is, a subset which contains all complex numbers whose modulus is sufficiently large.

Also see

 * Definition:Extended Complex Plane
 * Definition:Neighborhood of Infinity (Topology)