(* Constructions with gr_tl *************************************************)
(*** istot_tl *)
-lemma gr_ist_tl (f): ð\9d\90\93â\9dªfâ\9d« â\86\92 ð\9d\90\93â\9dªâ«±f❫.
+lemma gr_ist_tl (f): ð\9d\90\93â\9dªfâ\9d« â\86\92 ð\9d\90\93â\9dªâ«°f❫.
#f cases (gr_map_split_tl f) *
/2 width=3 by gr_ist_inv_next, gr_ist_inv_push/
qed.