reserve T for non empty TopSpace;
reserve A for Subset of T;

theorem Th51:
  { Int KurExSet, Int Cl KurExSet, Int Cl Int KurExSet } misses {
  Cl KurExSet, Cl Int KurExSet, Cl Int Cl KurExSet }
proof
  set X = { Int KurExSet, Int Cl KurExSet, Int Cl Int KurExSet }, Y = { Cl
  KurExSet, Cl Int KurExSet, Cl Int Cl KurExSet };
  assume X meets Y;
  then consider x being object such that
A1: x in X and
A2: x in Y by XBOOLE_0:3;
  x is open non empty Subset of R^1 & x is closed Subset of R^1 by A1,A2,Th48,
ENUMSET1:def 1;
  hence thesis by A1,Th49,BORSUK_5:34;
end;
