reserve p, q for Point of TOP-REAL 2,
  r for Real,
  h for non constant standard special_circular_sequence,
  g for FinSequence of TOP-REAL 2,
  f for non empty FinSequence of TOP-REAL 2,
  I, i1, i, j, k for Nat;

theorem
  for X being Subset of REAL st X = { q`2 : q in L~g } holds upper_bound
  X = upper_bound (proj2 | L~g) by Th18;
