-(*
- ||M|| This file is part of HELM, an Hypertextual, Electronic
- ||A|| Library of Mathematics, developed at the Computer Science
- ||T|| Department of the University of Bologna, Italy.
- ||I||
- ||T||
- ||A|| This file is distributed under the terms of the
- \ / GNU General Public License Version 2
- \ /
- V_______________________________________________________________ *)
-
-include "lambda-delta/syntax/lenv.ma".
-
-(* LENGTH *******************************************************************)
-
-(* the length of a local environment *)
-let rec length L ≝ match L with
-[ LSort ⇒ 0
-| LPair L _ _ ⇒ length L + 1
-].
-
-interpretation "length (local environment)" 'card L = (length L).