src/Tools/Code/code_haskell.ML

                 val consts = fold Code_Thingol.add_constnames (t :: ts) [];
                 val vars = reserved
                   |> intro_base_names
                       (is_none o syntax_const) deresolve consts
                   |> intro_vars ((fold o Code_Thingol.fold_varnames)
-                       (insert (op =)) ts []);
+                      (insert (op =)) ts []);
               in
                 semicolon (
                   (str o deresolve_base) name
                   :: map (pr_term tyvars thm vars BR) ts
                   @ str "="