src/Pure/ProofGeneral/preferences.ML

     "show-sorts"
     "Include sorts in display of Isabelle terms",
   bool_pref Goal_Display.show_consts_default
     "show-consts"
     "Show types of consts in Isabelle goal display",
-  bool_pref long_names
+  bool_pref Name_Space.long_names_default
     "long-names"
     "Show fully qualified names in Isabelle terms",
   bool_pref Printer.show_brackets_default
     "show-brackets"
     "Show full bracketing in Isabelle terms",