update in ground_2 and basic_2

[helm.git] / matita / matita / contribs / lambdadelta / ground_2 / lib / logic.ma

diff --git a/matita/matita/contribs/lambdadelta/ground_2/lib/logic.ma b/matita/matita/contribs/lambdadelta/ground_2/lib/logic.ma
new file mode 100644 (file)
index 0000000..852e4e9
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/ground_2/lib/logic.ma
@@ -0,0 +1,30 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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 "basics/logic.ma".
+include "ground_2/notation/xoa/false_0.ma".
+include "ground_2/notation/xoa/true_0.ma".
+include "ground_2/notation/xoa/or_2.ma".
+include "ground_2/notation/xoa/and_2.ma".
+include "ground_2/xoa/xoa.ma".
+
+interpretation "logical false" 'false = False.
+
+interpretation "logical true" 'true = True.
+
+(* Logical properties missing in the basic library **************************)
+
+lemma commutative_and: ∀A,B. A ∧ B → B ∧ A.
+#A #B * /2 width=1 by conj/
+qed-.