--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||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/list.ma".
+include "Basic_2/grammar/term.ma".
+
+(* GLOBAL ENVIRONMENTS ******************************************************)
+
+(* global environments *)
+definition genv ≝ list2 bind2 term.
+
+interpretation "sort (global environment)"
+ 'Star = (nil2 bind2 term).
+
+interpretation "environment binding construction (binary)"
+ 'DBind L I T = (cons2 bind2 term I T L).
+
+(* Basic properties *********************************************************)
+
+axiom genv_eq_dec: ∀T1,T2:genv. Decidable (T1 = T2).