- degree-based equivalene for terms

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / etc_2A1 / append / cix_append.etc

diff --git a/matita/matita/contribs/lambdadelta/basic_2/etc_2A1/append/cix_append.etc b/matita/matita/contribs/lambdadelta/basic_2/etc_2A1/append/cix_append.etc
new file mode 100644 (file)
index 0000000..7b5522e
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/etc_2A1/append/cix_append.etc
@@ -0,0 +1,26 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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 "basic_2/reduction/crx_append.ma".
+include "basic_2/reduction/cix.ma".
+
+(* IRREDUCIBLE TERMS FOR CONTEXT-SENSITIVE EXTENDED REDUCTION ***************)
+
+(* Advanced inversion lemmas ************************************************)
+
+lemma cix_inv_append_sn: ∀h,g,G,L,K,T. ⦃G, K @@ L⦄ ⊢ ➡[h, g] 𝐈⦃T⦄  → ⦃G, L⦄ ⊢ ➡[h, g] 𝐈⦃T⦄.
+/3 width=1 by crx_append_sn/ qed-.
+
+lemma cix_inv_tix: ∀h,g,G,L,T. ⦃G, L⦄ ⊢ ➡[h, g] 𝐈⦃T⦄  → ⦃G, ⋆⦄ ⊢ ➡[h, g] 𝐈⦃T⦄.
+/3 width=1 by trx_crx/ qed-.