Inductive plus: state -> state -> Prop :=
  | plus_left: forall s1 s2 s3,
      CCstep s1 s2 -> star s2 s3 -> plus s1 s3.Inductive plus: state -> state -> Prop :=
  | plus_left: forall s1 s2 s3,
      CCstep s1 s2 -> star s2 s3 -> plus s1 s3.

Lemma current_function_find_label: forall lbl f s k k', current_function k = Some f -> find_label lbl s k = Some k' -> current_function k' = Some f with current_function_find_label_ls: forall lbl f s k k', current_function k = Some f -> find_label_ls lbl s k = Some k' -> current_function k' = Some f.