1 (**************************************************************************)
4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
13 (**************************************************************************)
15 include "delayed_updating/reduction/ifr.ma".
17 include "delayed_updating/substitution/fsubst_lift.ma".
18 include "delayed_updating/substitution/fsubst_eq.ma".
19 include "delayed_updating/substitution/lift_prototerm_after.ma".
20 include "delayed_updating/substitution/lift_path_head.ma".
21 include "delayed_updating/substitution/lift_rmap_head.ma".
23 include "ground/relocation/tr_uni_compose.ma".
24 include "ground/relocation/tr_compose_eq.ma".
26 (* IMMEDIATE FOCUSED REDUCTION **********************************************)
28 (* Constructions with lift **************************************************)
30 theorem ifr_lift_bi (f) (t1) (t2) (r):
31 t1 ➡𝐢𝐟[r] t2 → ↑[f]t1 ➡𝐢𝐟[↑[f]r] ↑[f]t2.
33 * #p #q #k #Hr #H1k #Ht1 #Ht2 destruct
34 @(ex4_3_intro … (↑[f]p) (↑[↑[p◖𝗔◖𝗟]f]q) ((↑[p●𝗔◗𝗟◗q]f)@⧣❨k❩))
37 <lift_rmap_L_dx >lift_path_L_sn
38 <(lift_path_head_closed … H1k) in ⊢ (??%?); -H1k //
39 | lapply (in_comp_lift_path_term f … Ht1) -Ht2 -Ht1 -H1k
40 <lift_path_d_dx #Ht1 //
41 | lapply (lift_term_eq_repl_dx f … Ht2) -Ht2 #Ht2 -Ht1
42 @(subset_eq_trans … Ht2) -t2
43 @(subset_eq_trans … (lift_term_fsubst …))
44 @fsubst_eq_repl [ // | <lift_path_append // ]
45 @(subset_eq_canc_sn … (lift_term_eq_repl_dx …))
46 [ @lift_term_grafted_S | skip ]
47 @(subset_eq_trans … (lift_term_after …))
48 @(subset_eq_canc_dx … (lift_term_after …))
50 (* Note: crux of the proof begins *)
51 @(stream_eq_trans … (tr_compose_uni_dx …))
52 @tr_compose_eq_repl //
53 >list_append_rcons_sn in H1k; #H1k >lift_rmap_A_dx
54 /2 width=1 by tls_lift_rmap_closed/
55 (* Note: crux of the proof ends *)