src/Tools/Code/code_haskell.ML

   #> fold (Code_Target.add_reserved target) prelude_import_unqualified
   #> fold (Code_Target.add_reserved target o fst) prelude_import_unqualified_constr
   #> fold (fold (Code_Target.add_reserved target) o snd) prelude_import_unqualified_constr);
 
 val _ =
-  Outer_Syntax.command @{command_keyword code_monad} "define code syntax for monads"
+  Outer_Syntax.command \<^command_keyword>\<open>code_monad\<close> "define code syntax for monads"
     (Parse.term -- Parse.name >> (fn (raw_bind, target) =>
       Toplevel.theory (add_monad target raw_bind)));
 
 end; (*struct*)