Admitted. (* QuickChick S_nbeq_0 *)

(* Specifications: *)
Theorem mult_1_l : forall n:nat, 1 * n = n.
Admitted. (* QuickChick mult_1_l. *)
Theorem all3_spec : forall b c : bool,
orb
(andb b c)
(orb (negb b)
(negb c))
= true.