reserve T for non empty RelStr,
  A,B for Subset of T,
  x,x2,y,z for Element of T;

theorem Th28:
  for n being Nat holds Fcl(A`,n)` = Fint(A,n)
proof
  let n be Nat;
  Fint(A,n) = Fint(A``,n)`` .= Fcl(A`,n)` by Th27;
  hence thesis;
end;
