qed-.
(*** at_fwd_id_ex *)
-lemma gr_pat_des_id (f) (i): @â\9dªi,fâ\9d« â\89\98 i â\86\92 ⫯⫱f = f.
+lemma gr_pat_des_id (f) (i): @â\9dªi,fâ\9d« â\89\98 i â\86\92 ⫯⫰f = f.
#f elim (gr_map_split_tl f) //
#H #i #Hf elim (gr_pat_inv_next … Hf … H) -Hf -H
#j2 #Hg #H destruct lapply (gr_pat_increasing … Hg) -Hg