2022 Volume 14 Pages 139-142
The Lyapunov function plays an important role in the stability theory of dynamical systems. Its counterpart for discrete dynamical systems is not studied so much, though importance of such systems is increasing. In this letter, an attempt is made to construct a discrete analog of the Lyapunov function for the competitive Lotka-Volterra equation. For this purpose, a discrete logarithmic function is defined and its effectiveness is shown.