Local Hint Resolve lt_x'_x'max le_x'_x'max : a.

Lemma Meq_ir''0 : M = 1 -> _Z r''0 = 0.
intro H. cut (r''0 < 2 ^ p). rewrite p_M. rewrite H. simpl. cut (0 <= r''0). omega. apply le_0__Z. exact r''0_small. Qed.