X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fsyntax%2Fbind_weight.ma;fp=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fsyntax%2Fbind_weight.ma;h=2dda071d30290e9f4f9b139c2928c5f3e8868370;hb=73966e3e9fd17155ca67e6b4a32f52225cea9d3c;hp=0000000000000000000000000000000000000000;hpb=7632da8aa4f6751e351546be3d90fb23f634108c;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/basic_2/syntax/bind_weight.ma b/matita/matita/contribs/lambdadelta/basic_2/syntax/bind_weight.ma
new file mode 100644
index 000000000..2dda071d3
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/syntax/bind_weight.ma
@@ -0,0 +1,35 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/syntax/term.ma".
+
+(* BINDERS FOR LOCAL ENVIRONMENTS ******************************************)
+
+include "basic_2/syntax/term_weight.ma".
+include "basic_2/syntax/bind.ma".
+
+(* WEIGHT OF A BINDER FOR LOCAL ENVIRONMENTS *******************************)
+
+rec definition bw I ≝ match I with
+[ BUnit _   ⇒ 1
+| BPair _ V ⇒ ♯{V}
+].
+
+interpretation "weight (binder for local environments)" 'Weight I = (bw I).
+
+(* Basic properties *********************************************************)
+
+lemma bw_pos: ∀I. 1 ≤ ♯{I}.
+* //
+qed.