From: Ferruccio Guidi <ferruccio.guidi@unibo.it>
Date: Sun, 21 Apr 2013 15:52:11 +0000 (+0000)
Subject: one file was missing
X-Git-Tag: make_still_working~1180
X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=d1cf044d3f19bc9397872cc827cc77097fcc5b25;p=helm.git

one file was missing
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diff --git a/matita/matita/contribs/lambdadelta/basic_2/reduction/chnf.ma b/matita/matita/contribs/lambdadelta/basic_2/reduction/chnf.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 "basic_2/reduction/cpr_tshf.ma".
+
+(* CONTEXT-SENSITIVE WEAK HEAD NORMAL TERMS *********************************)
+
+definition chnf: lenv → predicate term ≝ λL. NF … (cpr L) tshf.
+
+interpretation
+   "context-sensitive head normality (term)"
+   'HdNormal L T = (chnf L T).
+
+(* Basic inversion lemmas ***************************************************)
+
+lemma chnf_inv_tshf: ∀L,T. L ⊢ 𝐇𝐍⦃T⦄ → T ≈ T.
+normalize /2 width=1/
+qed-.
+
+(* Basic properties *********************************************************)
+
+lemma tshf_thnf: ∀T. T ≈ T → ⋆ ⊢ 𝐇𝐍⦃T⦄.
+#T #HT #T2 #H elim (cpr_fwd_tshf1 … H) -H //
+#H elim H //
+qed.