(* QuickChick Prelude *)
Set Warnings "-extraction-opaque-accessed,-extraction".
Set Warnings "-notation-overridden,-parsing".
Set Bullet Behavior "Strict Subproofs".
(* End prelude *)
Require Export Basics.
Admitted. (* QuickChick plus_n_O_firsttry. *)
Admitted. (* QuickChick minus_diag. *)
Admitted. (* QuickChick mult_0_r. *)
Admitted. (* QuickChick plus_n_Sm. *)
Admitted. (* QuickChick plus_comm. *)
Admitted. (* QuickChick plus_comm *)
Fixpoint double (n:nat) :=
match n with
| O => O
| S n' => S (S (double n'))
end.

Lemma double_plus : forall n, double n = n + n .