src/HOL/Tools/BNF/bnf_gfp_grec_sugar_util.ML

--- a/src/HOL/Tools/BNF/bnf_gfp_grec_sugar_util.ML	Thu Dec 29 22:10:29 2016 +0100
+++ b/src/HOL/Tools/BNF/bnf_gfp_grec_sugar_util.ML	Fri Dec 30 15:40:35 2016 +0100
@@ -49,9 +49,6 @@
 
 val mk_case_sumN_balanced = Balanced_Tree.make mk_case_sum;
 
-fun not_codatatype ctxt T =
-  error ("Not a codatatype: " ^ Syntax.string_of_typ ctxt T);
-
 fun generalize_types max_j T U =
   let
     val vars = Unsynchronized.ref [];