matita/matita/contribs/lambdadelta/delayed_updating/unwind/unwind2_path_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/unwind/unwind2_path_eq.ma".
  16 include "delayed_updating/substitution/lift_eq.ma".
  17
  18 (* UNWIND FOR PATH **********************************************************)
  19
  20 (* Properties with lift_path ************************************************)
  21
  22 lemma unwind2_lift_path_after (p) (f1) (f2):
  23       ↑[f2]▼[f1]p = ▼[f2∘f1]p.
  24 #p @(path_ind_unwind … p) -p // [ #n | #p ] #IH #f1 #f2
  25 [ <unwind2_path_d_empty <unwind2_path_d_empty
  26   <lift_path_d_sn <lift_path_empty //
  27 | <unwind2_path_L_sn <unwind2_path_L_sn <lift_path_L_sn
  28   >tr_compose_push_bi //
  29 ]
  30 qed.