Quasi-asymptotic stability (source code)

= Quasi-asymptotic stability

An <equilibrium point> is quasi-asymptotically stable when some neighborhood of initial conditions has forward solutions converging to it. This attraction condition alone does not include <Lyapunov stability>. <Asymptotic stability> requires both attraction and Lyapunov stability. A positive <Lyapunov function> with nonpositive derivative and no nonstationary invariant trajectory in its zero-derivative set proves both when its sufficiently small sublevel sets are compact and forward invariant.