one can
observe five attractors. Two of them are symmetric pairs of rotations (1 : 3 resonance), two corresponds to symmetric 1 : 1
PO and the last one is the 1L1R PR. Next plot (m ¼ 1:2 and f¼0.75) includes seven attractors: two symmetric pairs of PR
(1 : 1 and 1 : 3), 4 : 3 PO, equilibrium of pendulum and 1L1R PR. I