+++ /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 "basics/list.ma".
-include "arithmetics/nat.ma".
-
-nlet rec length (A:Type) (l:list A) on l ≝
- match l with
- [ nil ⇒ 0
- | cons a tl ⇒ S (length A tl)].
-
-notation "|M|" non associative with precedence 60 for @{'norm $M}.
-interpretation "norm" 'norm l = (length ? l).
-
-nlet rec nth n (A:Type) (l:list A) (d:A) ≝
- match n with
- [O ⇒ hd A l d
- |S m ⇒ nth m A (tail A l) d].
-