theorem Th63:
  card bound_QC-variables(Al) = card QC-symbols(Al) &
  not bound_QC-variables(Al) is finite
proof
  NAT c= QC-symbols(Al) by QC_LANG1:3;
  then
A1: not QC-symbols(Al) is finite;
  bound_QC-variables(Al) = [: {4}, QC-symbols(Al) :] by QC_LANG1:def 4;
  then card bound_QC-variables(Al) = card [:QC-symbols(Al),{4}:] by CARD_2:4;
  hence thesis by A1,CARD_4:19;
end;
