doc-src/IsarAdvanced/Codegen/Thy/examples/Codegen.hs
changeset 25056 743f3603ba8b
parent 24628 33137422d7fd
child 25182 64e3f45dc6f4
     1.1 --- a/doc-src/IsarAdvanced/Codegen/Thy/examples/Codegen.hs	Tue Oct 16 17:06:21 2007 +0200
     1.2 +++ b/doc-src/IsarAdvanced/Codegen/Thy/examples/Codegen.hs	Tue Oct 16 17:07:40 2007 +0200
     1.3 @@ -10,8 +10,11 @@
     1.4  heada (x : xs) = x;
     1.5  heada [] = Codegen.nulla;
     1.6  
     1.7 +null_option :: Maybe a;
     1.8 +null_option = Nothing;
     1.9 +
    1.10  instance Codegen.Null (Maybe a) where {
    1.11 -  nulla = Nothing;
    1.12 +  nulla = Codegen.null_option;
    1.13  };
    1.14  
    1.15  dummy :: Maybe Nat.Nat;