include "delayed_updating/reduction/dfr.ma".
include "delayed_updating/reduction/ifr.ma".
include "delayed_updating/substitution/fsubst_lift.ma".
+include "delayed_updating/syntax/prototerm_proper_constructors.ma".
(* DELAYED FOCUSED REDUCTION ************************************************)
* #b * #Hb #Ht1 #Ht2
@(ex_intro … (⊗b)) @and3_intro
[ //
-| lapply (in_comp_lift_bi f … Ht1) -Ht1 #Ht1
-
-
-
-
+| lapply (in_comp_lift_bi f … Ht1) -Ht1 #Ht1
+| lapply (eq_lift_bi f … Ht2) -Ht2 #Ht2
+ @(subset_eq_trans … Ht2) -t2
+ @(subset_eq_trans … (lift_fsubst …))
+ [ <structure_append <structure_A_sn <structure_append <structure_L_sn
+ | //
+ | /2 width=2 by ex_intro/
+ | //
+ ]
+]
+