include "delayed_updating/unwind1/unwind_structure_depth.ma".
include "delayed_updating/unwind1/unwind_depth.ma".
include "delayed_updating/substitution/fsubst_eq.ma".
+include "delayed_updating/substitution/lift_prototerm_eq.ma".
include "delayed_updating/syntax/prototerm_proper_constructors.ma".
include "delayed_updating/syntax/path_structure_depth.ma".
include "ground/relocation/tr_uni_compose.ma".
<depth_append <depth_L_sn <depth_structure <depth_structure
@fsubst_eq_repl [ // ]
@(subset_eq_trans … (unwind_iref …))
+
+ elim Hb -Hb #Hb #H0 <H0 -H0 <nrplus_zero_dx <nplus_zero_dx <Hn
+ @(subset_eq_canc_sn … (lift_term_eq_repl_dx …))
+ [ @unwind_grafted_S /2 width=2 by ex_intro/ | skip ]
+
(*
@(subset_eq_canc_sn … (unwind_term_eq_repl_dx …))
[ @unwind_grafted_S /2 width=2 by ex_intro/ | skip ]