Figure 8: Activity of network A versus internal failure rate.
From: Multiple tipping points and optimal repairing in interacting networks
(a) Activity zA=1−aA obtained by solving equations (1) and (2), for a range of 
values, in a system of two interdependent networks (k=16, m=8). Blue lines correspond to stable physical states and red dotted lines represent unstable solutions. In Fig. 8a, the same parameters as in Fig. 1a are used, except 
, which is not fixed but varied. When 
(vertical black line), the corresponding values on the blue solid lines (green circles) match the graphical solutions in Fig. 1a (also green circles). (b) An analogous relationship holds between Figs 1b and 8b, in which case two stable states exist.
