helm/software/components/ng_kernel/test.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/plus.ma".
  16
  17 let rec f n :=
  18   match n with
  19   [ O => O
  20   | S m => let rec g x :=
  21              match x with
  22              [ O => f m
  23              | S q =>
  24                   let rec h y :=
  25                     match y with
  26                     [ O => f m + g q
  27                     | S w => h w]
  28                   in
  29                     h q]
  30            in
  31              g m].