set A1 = Cl KurExSet ;
set A2 = Cl (Int KurExSet );
set A3 = Cl (Int (Cl KurExSet ));
thus Cl KurExSet <> Cl (Int KurExSet ) by Th40; :: according to ZFMISC_1:def 5 :: thesis: ( not Cl KurExSet = Cl (Int (Cl KurExSet )) & not Cl (Int KurExSet ) = Cl (Int (Cl KurExSet )) )
thus Cl KurExSet <> Cl (Int (Cl KurExSet )) by Th31; :: thesis: not Cl (Int KurExSet ) = Cl (Int (Cl KurExSet ))
thus not Cl (Int KurExSet ) = Cl (Int (Cl KurExSet )) by Th33; :: thesis: verum