reserve a, b, k, n, m for Nat,
  i for Integer,
  r for Real,
  p for Rational,
  c for Complex,
  x for object,
  f for Function;

theorem
  rfs(r).(n+1) = rfs(1/frac(r)).n
proof
  frac(r) = r - scf(r).0 by Th35;
  hence thesis by Lm6;
end;
