matita/matita/contribs/lambdadelta/delayed_updating/syntax/path_inner.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
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  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/syntax/path.ma".
  16 include "delayed_updating/notation/functions/class_i_0.ma".
  17 include "ground/lib/subset.ma".
  18 include "ground/generated/insert_eq_1.ma".
  19
  20 (* INNER CONDITION FOR PATH *************************************************)
  21
  22 inductive pic: predicate path ≝
  23 | pic_empty: (𝐞) ϵ pic
  24 | pic_m_dx (p): p◖𝗺 ϵ pic
  25 | pic_L_dx (p): p◖𝗟 ϵ pic
  26 | pic_A_dx (p): p◖𝗔 ϵ pic
  27 | pic_S_dx (p): p◖𝗦 ϵ pic
  28 .
  29
  30 interpretation
  31   "inner condition (path)"
  32   'ClassI = (pic).
  33
  34 (* Basic inversions ********************************************************)
  35
  36 lemma pic_inv_d_dx (p) (k):
  37       p◖𝗱k ϵ 𝐈 → ⊥.
  38 #p #k @(insert_eq_1 … (p◖𝗱k))
  39 #q * -q [|*: #q ] #H0 destruct
  40 qed-.
  41
  42 (* Constructions with path_lcons ********************************************)
  43
  44 lemma pic_m_sn (p):
  45       p ϵ 𝐈 → 𝗺◗p ϵ 𝐈.
  46 #p * -p //
  47 qed.
  48
  49 lemma pic_L_sn (p):
  50       p ϵ 𝐈 → 𝗟◗p ϵ 𝐈.
  51 #p * -p //
  52 qed.
  53
  54 lemma pic_A_sn (p):
  55       p ϵ 𝐈 → 𝗔◗p ϵ 𝐈.
  56 #p * -p //
  57 qed.
  58
  59 lemma pic_S_sn (p):
  60       p ϵ 𝐈 → 𝗦◗p ϵ 𝐈.
  61 #p * -p //
  62 qed.