set A = KurExSet ;
( 2 in Cl (Int (Cl KurExSet)) & Int KurExSet = ].4,5.[ \/ ].5,+infty.[ ) by Th18, Th27, TOPS_1:def 1, XXREAL_1:236;
hence Cl (Int (Cl KurExSet)) <> Int KurExSet by XXREAL_1:223; :: thesis: verum