doc-src/IsarAdvanced/Codegen/Thy/examples/class.ML
changeset 21994 dfa5133dbe73
parent 21993 4b802a9e0738
child 22188 a63889770d57
--- a/doc-src/IsarAdvanced/Codegen/Thy/examples/class.ML	Thu Jan 04 17:11:09 2007 +0100
+++ b/doc-src/IsarAdvanced/Codegen/Thy/examples/class.ML	Thu Jan 04 17:17:48 2007 +0100
@@ -14,7 +14,8 @@
 type 'a null = {null_ : 'a};
 fun null (A_:'a null) = #null_ A_;
 
-fun head (A_:'a null) (y :: xs) = y;
+fun head (A_:'a null) (y :: xs) = y
+  | head (A_:'a null) [] = null A_;
 
 val null_option : 'b option = NONE;