Figure 2

The critical manifold and fold curves with their projections for g _K = 4 nS and g _BK = 0.4 nS. The curves L^- and L⁺ are the lower and upper fold curves, respectively. P(L^-) and P(L⁺) are the projections of L^- and L⁺ onto the upper and lower sheets of the critical manifold, respectively. FN is a folded node singularity, and SC (green curve) is the strong canard. The singular periodic orbit (black curve) is superimposed on the critical manifold.