Goal:
    p : positive  IHp : Z.of_nat (Pos.to_nat p) = Z.pos p
  ============================
   (Pos.of_succ_nat (Pos.to_nat p) = Pos.succ p)


DEBUG:Going to execute:
intros; Zify.zify_pre_hook; zify_elim_let; zify_op;
            Zify.zify_iter_specs