reserve n for Nat;

theorem Th25:
  for X,Y be non empty compact Subset of TOP-REAL 2 st S-bound X
  <= S-bound Y holds S-bound (X\/Y) = S-bound X
proof
  let X,Y be non empty compact Subset of TOP-REAL 2;
  assume S-bound X <= S-bound Y;
  then min(S-bound X,S-bound Y) = S-bound X by XXREAL_0:def 9;
  hence thesis by SPRECT_1:48;
end;
