reserve a, b for Real,
  r for Real,
  rr for Real,
  i, j, n for Nat,
  M for non empty MetrSpace,
  p, q, s for Point of TOP-REAL 2,
  e for Point of Euclid 2,
  w for Point of Euclid n,
  z for Point of M,
  A, B for Subset of TOP-REAL n,
  P for Subset of TOP-REAL 2,
  D for non empty Subset of TOP-REAL 2;
reserve a, b for Real;
reserve a, b for Real;
reserve r for Real;

theorem
  D is bounded implies S-bound D = S-bound Cl D
proof
A1: D c= Cl D by PRE_TOPC:18;
  assume
A2: D is bounded;
  then Cl D is compact by Th72;
  then proj2.:Cl D is bounded_below;
  then proj2.:D is bounded_below by A1,RELAT_1:123,XXREAL_2:44;
  then
A3: lower_bound (proj2.:D) = lower_bound Cl(proj2.:D) by Th66
    .= lower_bound (proj2.:Cl D) by A2,Th77;
  S-bound D = lower_bound (proj2.:D) by SPRECT_1:44;
  hence thesis by A3,SPRECT_1:44;
end;
