set A = KurExSet ;
( 2 in Cl (Int (Cl KurExSet )) & Int KurExSet = ].4,5.[ \/ ].5,+infty .[ ) by Th20, Th29, TOPS_1:def 1, XXREAL_1:236;
hence Cl (Int (Cl KurExSet )) <> Int KurExSet by XXREAL_1:223; :: thesis: verum