removed unused add_in_order/add_once (cf. OrdList.insert);
removed unused add_in_order/add_once (cf. OrdList.insert);

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle