revert i j; induction v; intros i j Hi.
+ cbn; intros ? % divides_1_inv % not_qs_1; auto.
+ cbn; intros [ H % divides_pow | H  ] % divides_mult_inv; eauto.
* eapply primestream_divides in H; omega.
* eapply IHv in H; eauto.
Qed.

Lemma exp_inj n i v1 v2 :
@exp n i v1 = exp i v2 -> v1 = v2.