src/HOL/Orderings.thy

   in
     Pretty.writeln (Pretty.big_list "order structures:" (map pretty_struct structs))
   end;
 
 val _ =
-  Outer_Syntax.improper_command @{command_spec "print_orders"}
+  Outer_Syntax.command @{command_spec "print_orders"}
     "print order structures available to transitivity reasoner"
     (Scan.succeed (Toplevel.unknown_context o
       Toplevel.keep (print_structures o Toplevel.context_of)));