In complex plane, paths {closed contour} can loop around origin. There is line integral {contour integration} around the path. Looping once increases integral by 2 * pi * i. Looping counterclockwise once increases integral by -2 * pi * i.
Mathematical Sciences>Calculus>Integration>Line>Complex
3-Calculus-Integration-Line-Complex
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0224