
theorem
  for a,b being object st a <> b holds
  canFS({a,b}) = <*a,b*> or canFS({a,b}) = <*b,a*>
  proof
    let a,b be object;
    rng canFS({a,b}) = {a,b} by FUNCT_2:def 3;
    hence thesis by FINSEQ_3:99;
  end;
