milestone update in ground

[helm.git] / matita / matita / contribs / lambdadelta / ground / relocation / gr_after_isi.ma

diff --git a/matita/matita/contribs/lambdadelta/ground/relocation/gr_after_isi.ma b/matita/matita/contribs/lambdadelta/ground/relocation/gr_after_isi.ma
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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||M||                                                             *)
+(*      ||A||       A project by Andrea Asperti                           *)
+(*      ||T||                                                             *)
+(*      ||I||       Developers:                                           *)
+(*      ||T||         The HELM team.                                      *)
+(*      ||A||         http://helm.cs.unibo.it                             *)
+(*      \   /                                                             *)
+(*       \ /        This file is distributed under the terms of the       *)
+(*        v         GNU General Public License Version 2                  *)
+(*                                                                        *)
+(**************************************************************************)
+
+include "ground/relocation/gr_isi.ma".
+include "ground/relocation/gr_after_after.ma".
+
+(* RELATIONAL COMPOSITION FOR GENERIC RELOCATION MAPS ***********************************************************)
+
+(* Properties on isid *******************************************************)
+
+(*** after_isid_sn *)
+corec lemma gr_after_isi_sn:
+            ∀f1. 𝐈❪f1❫ → ∀f2. f1 ⊚ f2 ≘ f2.
+#f1 * -f1
+#f1 #g1 #Hf1 #H1 #f2 cases (gr_map_split_tl f2) #H2
+/3 width=7 by gr_after_push, gr_after_refl/
+qed.
+
+(*** after_isid_dx *)
+corec lemma gr_after_isi_dx:
+            ∀f2. 𝐈❪f2❫ → ∀f1. f1 ⊚ f2 ≘ f1.
+#f2 * -f2
+#f2 #g2 #Hf2 #H2 #f1 cases (gr_map_split_tl f1) #H1
+[ /3 width=7 by gr_after_refl/
+| @(gr_after_next … H1 H1) /3 width=3 by gr_isi_push/
+]
+qed.
+
+(* Destructions on isid *************************************************)
+
+(*** after_isid_inv_sn *)
+lemma gr_after_isi_inv_sn:
+      ∀f1,f2,f. f1 ⊚ f2 ≘ f → 𝐈❪f1❫ → f2 ≡ f.
+/3 width=6 by gr_after_isi_sn, gr_after_mono/ qed-.
+
+(*** after_isid_inv_dx *)
+lemma gr_after_isi_inv_dx:
+      ∀f1,f2,f. f1 ⊚ f2 ≘ f → 𝐈❪f2❫ → f1 ≡ f.
+/3 width=6 by gr_after_isi_dx, gr_after_mono/ qed-.
+
+(*** after_fwd_isid1 *)
+corec lemma gr_after_des_isi_sn:
+            ∀f1,f2,f. f1 ⊚ f2 ≘ f → 𝐈❪f❫ → 𝐈❪f1❫.
+#f1 #f2 #f * -f1 -f2 -f
+#f1 #f2 #f #g1 [1,2: #g2 ] #g #Hf #H1 [1,2: #H2 ] #H0 #H
+[ /4 width=6 by gr_isi_inv_push, gr_isi_push/ ]
+cases (gr_isi_inv_next … H … H0)
+qed-.
+
+(*** after_fwd_isid2 *)
+corec lemma gr_after_des_isi_dx:
+            ∀f1,f2,f. f1 ⊚ f2 ≘ f → 𝐈❪f❫ → 𝐈❪f2❫.
+#f1 #f2 #f * -f1 -f2 -f
+#f1 #f2 #f #g1 [1,2: #g2 ] #g #Hf #H1 [1,2: #H2 ] #H0 #H
+[ /4 width=6 by gr_isi_inv_push, gr_isi_push/ ]
+cases (gr_isi_inv_next … H … H0)
+qed-.
+
+(*** after_inv_isid3 *)
+lemma gr_after_inv_isi:
+      ∀f1,f2,f. f1 ⊚ f2 ≘ f → 𝐈❪f❫ → 𝐈❪f1❫ ∧ 𝐈❪f2❫.
+/3 width=4 by gr_after_des_isi_dx, gr_after_des_isi_sn, conj/ qed-.