- degree-based equivalene for terms

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

diff --git a/matita/matita/contribs/lambdadelta/basic_2/etc_2A1/append/cir_append.etc b/matita/matita/contribs/lambdadelta/basic_2/etc_2A1/append/cir_append.etc
new file mode 100644 (file)
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+++ b/matita/matita/contribs/lambdadelta/basic_2/etc_2A1/append/cir_append.etc
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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 "basic_2/reduction/crr_append.ma".
+include "basic_2/reduction/cir.ma".
+
+(* IRREDUCIBLE TERMS FOR CONTEXT-SENSITIVE REDUCTION ************************)
+
+(* Advanved properties ******************************************************)
+
+lemma cir_labst_last: ∀G,L,T,W. ⦃G, L⦄ ⊢ ➡ 𝐈⦃T⦄  → ⦃G, ⋆.ⓛW @@ L⦄ ⊢ ➡ 𝐈⦃T⦄.
+/3 width=2 by crr_inv_labst_last/ qed.
+
+lemma cir_tif: ∀G,T,W. ⦃G, ⋆⦄ ⊢ ➡ 𝐈⦃T⦄ → ⦃G, ⋆.ⓛW⦄ ⊢ ➡ 𝐈⦃T⦄.
+/3 width=2 by crr_inv_trr/ qed.
+
+(* Advanced inversion lemmas ************************************************)
+
+lemma cir_inv_append_sn: ∀G,L,K,T. ⦃G, K @@ L⦄ ⊢ ➡ 𝐈⦃T⦄  → ⦃G, L⦄ ⊢ ➡ 𝐈⦃T⦄.
+/3 width=1/ qed-.
+
+lemma cir_inv_tir: ∀G,T,W. ⦃G, ⋆.ⓛW⦄ ⊢ ➡ 𝐈⦃T⦄  → ⦃G, ⋆⦄ ⊢ ➡ 𝐈⦃T⦄.
+/3 width=1/ qed-.