 Lyapunov function

A Lyapunov function near an equilibrium $x^{\ast }$ is continuously differentiable, satisfies $V(x^{\ast })=0$ and $V(x)>0$ away from $x^{\ast }$, and has orbital derivative

A Lyapunov function is a mathematical construct used in the field of stability theory to analyze the stability of dynamic systems, particularly in the context of differential equations and control theory. It is a scalar function that helps in determining the stability of an equilibrium point of a dynamical system.