Horseshoe and entropy for C1 surface diffeomorphisms

Let M be a two-dimensional closed Riemannian manifold and denote by Diff(1)(M) the set of C-1 diffeomorphisms on M. Then, the C-1 interior of {f is an element of Diff(1) (M) : h(f) = 0} is equal to the C-1 interior of the closure of the Morse-Smale systems and equal to the C-1 interior of the set of diffeomorphisms having no horseshoe.