reserve n for Nat;

theorem Th26:
  for X,Y be non empty compact Subset of TOP-REAL 2 st W-bound X
  <= W-bound Y holds W-bound (X\/Y) = W-bound X
proof
  let X,Y be non empty compact Subset of TOP-REAL 2;
  assume W-bound X <= W-bound Y;
  then min(W-bound X,W-bound Y) = W-bound X by XXREAL_0:def 9;
  hence thesis by SPRECT_1:47;
end;
