reserve i for Nat,
  j for Element of NAT,
  X,Y,x,y,z for set;

theorem Th24:
  for A being finite Subset of Vars holds varcl A is finite Subset of Vars
proof
  let A be finite Subset of Vars;
  A c= Rank omega by Th23;
  then A in Rank omega by Th22;
  then the_rank_of A in omega by CLASSES1:66;
  then the_rank_of varcl A is finite by Th21;
  hence thesis by Th9,Th19,Th20;
end;
