(* Import the AST of this C program *)
(* The next line is "boilerplate", always required after importing an AST. *)
Instance CompSpecs : compspecs.Definition Vprog : varspecs.(* Functional spec of this program.  *)
Definition sum_Z : list Z -> Z := fold_right Z.add 0.

Lemma sum_Z_app: forall a b, sum_Z (a++b) = sum_Z a + sum_Z b.