src/Pure/tactic.ML

      separated by blanks ***)
 
 (*Calling this will generate the warning "Same as previous level" since
   it affects nothing but the names of bound variables!*)
 fun rename_params_tac xs i =
-  case Library.find_first (not o Symbol.is_identifier) xs of
+  case Library.find_first (not o Syntax.is_identifier) xs of
       Some x => error ("Not an identifier: " ^ x)
     | None => 
        (if !Logic.auto_rename
 	 then (warning "Resetting Logic.auto_rename";
 	     Logic.auto_rename := false)