A region is a nonempty open subset of . Note that this definition is a of that of domain ( (as defined in complex analysis) to the complex plane. Some people prefer to use “region” instead of “domain” to avoid confusion with other mathematical definitions of domain. (The set theoretic definition of domain ( is also used in complex analysis.)

Regions play a major role in complex analysis since every nonempty open subset of is the union of countably many connected componentsMathworldPlanetmathPlanetmathPlanetmath, each of which is a region.

Title region
Canonical name Region
Date of creation 2013-03-22 11:56:19
Last modified on 2013-03-22 11:56:19
Owner Wkbj79 (1863)
Last modified by Wkbj79 (1863)
Numerical id 11
Author Wkbj79 (1863)
Entry type Definition
Classification msc 30-00
Related topic Complex
Related topic Domain2