Lyapunov function


Lyapunov function

[lē′ap·ə‚nȯf ‚fəŋk·shən] (mathematics) A function of a vector and of time which is positive-definite and has a negative-definite derivative with respect to time for nonzero vectors, is identically zero for the zero vector, and approaches infinity as the norm of the vector approaches infinity; used in determining the stability of control systems. Also spelled Liapunov function.