helm/software/matita/tests/diabolic_fix.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
  17 definition f :=
  18  λs1,s2:nat.
  19    let rec aux (s3:nat → nat) (x:nat) on x :=
  20      match x with
  21      [ O ⇒ s3 (S x)
  22      | S m ⇒ aux2 s3 m]
  23     and aux2 (s3:nat → nat) (x:nat) on x :=
  24      match x with
  25      [ O ⇒ s3 x
  26      | S m ⇒ aux s3 m]
  27     in aux.
  28
  29 definition g :=
  30  λw.