matita/matita/contribs/lambdadelta/delayed_updating/unwind/unwind2_path_inner.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_structure.ma".
  16 include "delayed_updating/syntax/path_inner.ma".
  17
  18 (* UNWIND FOR PATH **********************************************************)
  19
  20 (* Destructions with inner condition for path *******************************)
  21
  22 lemma unwind2_path_des_inner (f) (p):
  23       ▼[f]p ϵ 𝐈 → p ϵ 𝐈.
  24 #f #p @(list_ind_rcons … p) -p //
  25 #p * [ #n ] #_ //
  26 <unwind2_path_d_dx #H0
  27 elim (pic_inv_d_dx … H0)
  28 qed-.