A "distinctor elimination" lemma with no disjoint variable conditions on variables in the consequent. (Contributed by NM, 8-Nov-2006.) Remove dependency on [ax-11]. (Revised by Wolf Lammen, 7-Sep-2018.) Remove dependency on [ax-13], inspired by an idea of BJ. (Revised by Wolf Lammen, 30-Nov-2019.) Remove dependency on [ax-12]. (Revised by Wolf Lammen, 19-Mar-2021.)