- degree-based equivalene for terms

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / syntax / genv.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/syntax/genv.ma b/matita/matita/contribs/lambdadelta/basic_2/syntax/genv.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 "ground_2/lib/list2.ma".
+include "basic_2/notation/constructors/star_0.ma".
+include "basic_2/notation/constructors/dxbind2_3.ma".
+include "basic_2/notation/constructors/dxabbr_2.ma".
+include "basic_2/notation/constructors/dxabst_2.ma".
+include "basic_2/syntax/term.ma".
+
+(* GLOBAL ENVIRONMENTS ******************************************************)
+
+(* global environments *)
+definition genv ≝ list2 bind2 term.
+
+interpretation "sort (global environment)"
+   'Star = (nil2 bind2 term).
+
+interpretation "global environment binding construction (binary)"
+   'DxBind2 L I T = (cons2 bind2 term I T L).
+
+interpretation "abbreviation (global environment)"
+   'DxAbbr L T = (cons2 bind2 term Abbr T L).
+
+interpretation "abstraction (global environment)"
+   'DxAbst L T = (cons2 bind2 term Abst T L).
+
+(* Basic properties *********************************************************)
+
+axiom eq_genv_dec: ∀G1,G2:genv. Decidable (G1 = G2).