(** Definitions of some environments **)
Definition empty_genv cenv := Build_genv (Globalenvs.Genv.empty_genv fundef type nil) cenv.Definition empty_tenv := PTree.empty val.Definition empty_environ cenv : environ :=
mkEnviron (filter_genv (empty_genv cenv)) (Map.empty _) (Map.empty _).

Lemma Zle_bool_rev: forall x y, Zle_bool x y = Zge_bool y x.