(** ** Lemmas about erased values*)

  Definition isDefined v :=
    match v with
    | Vundef => false
    | _ => true
    end.

Lemma repeat_Undef_inject_encode_val : forall (chunk : memory_chunk) (v : val), memval_erasure_list (list_repeat (size_chunk_nat chunk) Undef) (encode_val chunk v).