assumption. Qed.

(* Specifications: *)
Lemma M1_h'_i_eq : M = 1 -> _Z h'_i = x_i.
intro H. unfold h'_i. rewrite Z_from_plusw. rewrite M1_h_i_eq. unfold s''_i. rewrite ltw_true. unfold s_i. simpl. fold p.