update in static_2

[helm.git] / matita / matita / contribs / lambdadelta / static_2 / syntax / acle.ma

diff --git a/matita/matita/contribs/lambdadelta/static_2/syntax/acle.ma b/matita/matita/contribs/lambdadelta/static_2/syntax/acle.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 "static_2/syntax/ac.ma".
+
+(* APPLICABILITY CONDITION PREORDER *****************************************)
+
+definition acle: relation ac ≝
+           λa1,a2. ∀m. ad a1 m → ∃∃n. ad a2 n & m ≤ n.
+
+interpretation "preorder (applicability domain)"
+  'subseteq a1 a2 = (acle a1 a2).
+
+(* Basic properties *********************************************************)
+
+lemma acle_refl: reflexive … acle.
+/2 width=3 by ex2_intro/ qed.
+
+lemma acle_omega (a): a ⊆ 𝛚.
+/2 width=1 by acle_refl/
+qed.
+
+lemma acle_one (a): ∀n. ad a n → 𝟏 ⊆ a.
+#a #n #Ha #m #Hm destruct
+/2 width=3 by ex2_intro/
+qed.
+
+lemma acle_eq_monotonic_le (k1) (k2):
+      k1 ≤ k2 → (ac_eq k1) ⊆ (ac_eq k2).
+#k1 #k2 #Hk #m #Hm destruct
+/2 width=3 by ex2_intro/
+qed.
+
+lemma acle_le_monotonic_le (k1) (k2):
+      k1 ≤ k2 → (ac_le k1) ⊆ (ac_le k2).
+#k1 #k2 #Hk #m #Hm
+/3 width=3 by acle_refl, transitive_le/
+qed.
+
+lemma acle_eq_le (k): (ac_eq k) ⊆ (ac_le k).
+#k #m #Hm destruct
+/2 width=1 by acle_refl, le_n/
+qed.
+
+lemma acle_le_eq (k): (ac_le k) ⊆ (ac_eq k).
+#k #m #Hm /2 width=3 by ex2_intro/
+qed.