  The paper is a continuation of research in the direction of energy function
(a smooth Lyapunov function whose set of critical points coincides with the
chain recurrent set of a system) construction for discrete dynamical systems.
The authors established the existence of an energy function for any $ A
$-diffeomorphism of a three-dimensional closed orientable manifold whose
non-wandering set consists of chaotic one-dimensional attractor and repeller.
