Editing Limit cycle (section)

==Properties==
By the [[Jordan curve theorem]], every closed trajectory divides the plane into two regions, the interior and the exterior of the curve.

Given a limit cycle and a trajectory in its interior that approaches the limit cycle for time approaching <math>+ \infty</math>, then there is a neighborhood around the limit cycle such that ''all'' trajectories in the interior that start in the neighborhood approach the limit cycle for time approaching <math> + \infty</math>. The corresponding statement holds for a trajectory in the interior that approaches the limit cycle for time approaching <math>- \infty</math>, and also for trajectories in the exterior approaching the limit cycle.