module Codegen where {

 import qualified Nat;

 class Null a where {

   nulla :: a;

 };

 heada :: forall a. (Codegen.Null a) => [a] -> a;

 heada (x : xs) = x;

 heada [] = Codegen.nulla;

 null_option :: forall a. Maybe a;

 null_option = Nothing;

 instance Codegen.Null (Maybe a) where {

   nulla = Codegen.null_option;

 };

 dummy :: Maybe Nat.Nat;

 dummy = Codegen.heada [Just (Nat.Suc Nat.Zero_nat), Nothing];

 }