+#f #p #q #t1 #t2 #H0t1
+* #b #n * #Hb #Hn #Ht1 #Ht2
+@(ex1_2_intro … (⊗b) (↑❘⊗q❘)) @and4_intro
+[ //
+| #g <lift_rmap_structure <depth_structure
+ >tr_pushs_swap <tr_pap_pushs_le //
+| lapply (in_comp_lift_bi f … Ht1) -Ht1 -H0t1 -Hb -Ht2
+ <lift_d_empty_dx //
+| lapply (lift_term_eq_repl_dx f … Ht2) -Ht2 #Ht2
+ @(subset_eq_trans … Ht2) -t2
+ @(subset_eq_trans … (lift_fsubst …))
+ [ <structure_append <structure_A_sn <structure_append <structure_L_sn
+ @fsubst_eq_repl [ // ]
+ @(subset_eq_trans … (lift_iref …))
+ | //
+ | /2 width=2 by ex_intro/
+ | //
+ ]
+]