take Kurat7Set ({} T) ; :: thesis: ( Kurat7Set ({} T) is Int-closed & Kurat7Set ({} T) is Cl-closed & not Kurat7Set ({} T) is empty )
thus ( Kurat7Set ({} T) is Int-closed & Kurat7Set ({} T) is Cl-closed & not Kurat7Set ({} T) is empty ) ; :: thesis: verum