matita/matita/contribs/lambdadelta/delayed_updating/reduction/ifr_lift.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
   7 (*      ||T||         The HELM team.                                      *)
   8 (*      ||A||         http://helm.cs.unibo.it                             *)
   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 include "delayed_updating/reduction/ifr.ma".
  16
  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_closed.ma".
  21 include "delayed_updating/substitution/lift_rmap_closed.ma".
  22
  23 include "ground/relocation/tr_uni_compose.ma".
  24 include "ground/relocation/tr_compose_eq.ma".
  25
  26 (* IMMEDIATE FOCUSED REDUCTION **********************************************)
  27
  28 (* Constructions with lift **************************************************)
  29
  30 theorem ifr_lift_bi (f) (t1) (t2) (r):
  31         t1 ➡𝐢𝐟[r] t2 → 🠡[f]t1 ➡𝐢𝐟[🠡[f]r] 🠡[f]t2.
  32 #f #t1 #t2 #r
  33 * #p #q #n #Hr #Hn #Ht1 #Ht2 destruct
  34 @(ex4_3_intro … (🠡[f]p) (🠡[🠢[f](p◖𝗔◖𝗟)]q) (🠢[f](p●𝗔◗𝗟◗q)＠§❨n❩))
  35 [ -Hn -Ht1 -Ht2 //
  36 | -Ht1 -Ht2
  37   /2 width=1 by lift_path_rmap_closed_L/
  38 | lapply (in_comp_lift_path_term f … Ht1) -Ht2 -Ht1 -Hn
  39   <lift_path_d_dx #Ht1 //
  40 | lapply (lift_term_eq_repl_dx f … Ht2) -Ht2 #Ht2 -Ht1
  41   @(subset_eq_trans … Ht2) -t2
  42   @(subset_eq_trans … (lift_term_fsubst …))
  43   @fsubst_eq_repl [ // | <lift_path_append // ]
  44   @(subset_eq_canc_sn … (lift_term_eq_repl_dx …))
  45   [ @lift_term_grafted_S | skip ]
  46   @(subset_eq_trans … (lift_term_after …))
  47   @(subset_eq_canc_dx … (lift_term_after …))
  48   @lift_term_eq_repl_sn
  49 (* Note: crux of the proof begins *)
  50   @(stream_eq_trans … (tr_compose_uni_dx_pap …)) <tr_pap_succ_nap
  51   @tr_compose_eq_repl // >nsucc_unfold
  52   /2 width=2 by tls_succ_lift_rmap_append_closed_Lq_dx/
  53 (* Note: crux of the proof ends *)
  54 ]
  55 qed.