matita/matita/contribs/lambdadelta/delayed_updating/etc/unwind3/unwind_length.etc

   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/unwind3/unwind.ma".
  16 include "delayed_updating/syntax/path_depth.ma".
  17 include "ground/lib/stream_tls_plus.ma".
  18 include "ground/lib/stream_eq.ma".
  19 (*
  20 include "ground/relocation/tr_uni_compose.ma".
  21 include "ground/lib/stream_eq_eq.ma".
  22 *)
  23 (* UNWIND FOR PATH **********************************************************)
  24
  25 (* Constructions with list_length ********************************************)
  26
  27 axiom tls_unwind (p) (f):
  28       f ≗ ⇂*[❘p❘]▼[p]f.
  29 (* COMMENT
  30 #q @(list_ind_rcons … q) -q //
  31 #q * [ #n ] #IH #f //
  32 <depth_d_dx >list_cons_shift <list_append_assoc <unwind_rmap_d_dx
  33 /3 width=3 by tr_tls_compose_uni_sn, stream_eq_trans/
  34 qed.
  35 *)