The _dynamics_ of the system is expressed by the two time series \\(X[t]\\) and \\(X_2[t]\\).

Intuitively, we would expect that given a starting state \\(S[0] = (X[0], X_2[0])\\), it will eventually approach some limiting state \\(S[{\infty}] = (X', X_2')\\) as \\(t\\) advances - that is the _equilibrium_ state towards which it is bound.