Hint Rewrite @sublist_nil' using list_solve: sublist.
Hint Rewrite @app_nil_l : sublist.
Hint Rewrite @Zlength_rev : sublist.
Hint Rewrite @sublist_rejoin' using list_solve : sublist.

Lemma upd_Znth0 {A} (l:list A) v:
upd_Znth 0 l v = v :: sublist 1 (Zlength l) l.