X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fsyntax%2Fgenv_weight.ma;fp=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fsyntax%2Fgenv_weight.ma;h=632fdc8e53ca7ddd26d9a02b0a0dcb11b958fd4c;hb=48c011f52853dd106dbf9cbbd1b9da61277fba3b;hp=0000000000000000000000000000000000000000;hpb=e880d6eab5e1700f4a625ddcd7d0fa8f0cce2dcc;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/basic_2/syntax/genv_weight.ma b/matita/matita/contribs/lambdadelta/basic_2/syntax/genv_weight.ma
new file mode 100644
index 000000000..632fdc8e5
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/syntax/genv_weight.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 "basic_2/syntax/term_weight.ma".
+include "basic_2/syntax/genv.ma".
+
+(* WEIGHT OF A GLOBAL ENVIRONMENT *******************************************)
+
+rec definition gw G ≝ match G with
+[ GAtom       ⇒ 0
+| GPair G I T ⇒ gw G + ♯{T}
+].
+
+interpretation "weight (global environment)" 'Weight G = (gw G).
+
+(* Basic properties *********************************************************)
+
+lemma gw_pair: ∀I,G,T. ♯{G} < ♯{G.ⓑ{I}T}.
+normalize /2 width=1 by monotonic_le_plus_r/ qed.