propagating the arithmetics library, partial commit

[helm.git] / matita / matita / contribs / lambdadelta / ground / etc / ynat_old / ynat_iszero.etc

diff --git a/matita/matita/contribs/lambdadelta/ground/etc/ynat_old/ynat_iszero.etc b/matita/matita/contribs/lambdadelta/ground/etc/ynat_old/ynat_iszero.etc
deleted file mode 100644 (file)
index 3cb47bc..0000000
--- a/matita/matita/contribs/lambdadelta/ground/etc/ynat_old/ynat_iszero.etc
+++ /dev/null
@@ -1,35 +0,0 @@
-(**************************************************************************)
-(*       ___                                                              *)
-(*      ||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_2/notation.ma".
-include "ground_2/xoa_props.ma".
-include "ground_2/ynat/ynat.ma".
-
-(* INFINITARY NATURAL NUMBERS ***********************************************)
-
-(* "is_zero" predicate *)
-definition yzero: predicate ynat ≝ λx. match x with
-[ YO   ⇒ ⊤
-| YS _ ⇒ ⊥
-].
-
-(* Inversion lemmas *********************************************************)
-
-lemma discr_YS_YO: ∀n. ⫯n = 0 → ⊥.
-#n #H change with (yzero (⫯n))
->H -H //
-qed-.
-
-lemma discr_YO_YS: ∀n. ynat_of_nat 0 = ⫯n → ⊥. (**) (* explicit coercion *)
-/2 width=2 by discr_YS_YO/ qed-.