Sei ${\displaystyle {}v\in U}$. Dann ist

${\displaystyle {}(\varphi -\lambda \operatorname {Id} _{V})(v)=\varphi (v)-\lambda v\,.}$

${\displaystyle {}\varphi (v)\in U}$

${\displaystyle {}\lambda v\in U}$

${\displaystyle {}U}$