      ![The dynamics of the observables $a,\ H,\ u,\ x,\ R,\ X,\ \rho,\ \ddot a$, showing the effects of the parameter $w_{0-0}$. The red tiny dashed line is for $w_{0-0}=0$, the orange long dashed line is for $w_{0-0}=0.0$, the gray solid line is for $w_{0-0}=0$, the green medium dashed line line is for $w_{0-0}=-0.0$, and the blue dot-dashed is for $w_{0-0}=-0$.](