theorem Th85:
  [S,x] is quantifiable implies @(CQCSub_All([S,x],xSQ))`2 = @
RestrictSub(x,All(x,S`1),xSQ) +* (@xSQ)|RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x
  ,S`1),xSQ)
proof
  set S1 = CQCSub_All([S,x],xSQ);
A1: (@xSQ)|RSub2(All(x,S`1),xSQ) c= @xSQ by RELAT_1:59;
  dom ((@xSQ)|RSub1(All(x,S`1))) misses dom ((@xSQ)|RSub2(All(x,S`1),xSQ))
  by Th82;
  then
A2: ((@xSQ)|RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x,S`1),xSQ)) = ((@xSQ)|
  RSub1(All(x,S`1)) \/ (@xSQ)|RSub2(All(x,S`1),xSQ)) by FUNCT_4:31;
  assume
A3: [S,x] is quantifiable;
  then S1 = Sub_All([S,x],xSQ) by Def5;
  then
A4: @S1`2 = @xSQ by A3,Th26;
A5: @RestrictSub(x,All(x,S`1),xSQ) = @xSQ \ ((@xSQ)|RSub1(All(x,S`1)) +* (@
  xSQ)|RSub2(All(x,S`1),xSQ)) by Th83;
  then reconsider
  F = @xSQ \ ((@xSQ)|RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x,S`1),
  xSQ)) as PartFunc of bound_QC-variables(Al),bound_QC-variables(Al);
  dom F misses (dom ((@xSQ)|RSub1(All(x,S`1))) \/ dom ((@xSQ)|RSub2(All(x
  ,S`1),xSQ))) by A5,Th84;
  then
A6: dom F misses dom ((@xSQ)|RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x,S`1),
  xSQ)) by FUNCT_4:def 1;
  ((@xSQ)|RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x,S`1),xSQ)) \/ F = ((@xSQ
  )| RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x,S`1),xSQ)) \/ @xSQ & (@xSQ)|RSub1(
  All( x,S`1)) c= @xSQ by RELAT_1:59,XBOOLE_1:39;
  then
  ((@xSQ)|RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x,S`1),xSQ)) \/ F = @ xSQ
  by A2,A1,XBOOLE_1:8,12;
  then F +* ((@xSQ)|RSub1(All(x,S`1)) +* (@xSQ)|RSub2(All(x,S`1),xSQ)) = @xSQ
  by A6,FUNCT_4:31;
  hence thesis by A4,A5,FUNCT_4:14;
end;
