Fig. 1

Example of a two-dimensional phase space (described by two variables ξ and η) of a dynamic system that has three attractors: stable point attractor (0); stable limit cycle (solid line, 1); unstable limit cycle (dashed line, 2). Unstable cycle 2 separates basins of attraction of stable attractors 0 and 1. Trajectories correspond to lines with arrows; the limit cycles 1 and 2 also constitute trajectories. This may represent a two-dimensional subspace of a multi-dimensional phase space