matita/tests/fix_che_non_passa_ma_dovrebbe.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
   7 (*      ||T||         The HELM team.                                      *)
   8 (*      ||A||         http://helm.cs.unibo.it                             *)
   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 include "nat/nat.ma".
  16 include "list/list.ma".
  17
  18 let rec cazzo (l:list nat) (f:list nat -> nat -> nat) (x:nat) on l :=
  19   match l with [ nil => x
  20   | cons hd tl => cazzo tl f (f tl x)].
  21
  22 let rec f (l:list nat) (x:nat) on l  :=
  23   match l with
  24   [ nil => x
  25   | cons hd tl => cazzo tl f x].