src/Pure/Syntax/syntax.ML

   let
     val {print_trtab, print_ruletab, print_ast_trtab, tokentrtab, prtabs, ...} = tabs;
     val ast = t_to_ast ctxt (lookup_tr' print_trtab) t;
   in
     Pretty.markup markup (prt_t ctxt curried prtabs (lookup_tr' print_ast_trtab)
-      (lookup_tokentr tokentrtab (! print_mode))
+      (lookup_tokentr tokentrtab (print_mode_value ()))
       (Ast.normalize_ast (Symtab.lookup_list print_ruletab) ast))
   end;
 
 fun pretty_term extern =
   pretty_t Printer.term_to_ast (Printer.pretty_term_ast extern) Markup.term;