Seifert, ChristianChristianSeifertTrostorff, SaschaSaschaTrostorffWaurick, MarcusMarcusWaurick2022-02-222022-02-222022Operator Theory: Advances and Applications 287: 15-30 (2022)http://hdl.handle.net/11420/11744We will gather some information on operators in Banach and Hilbert spaces. Throughout this chapter let X0, X1, and X2 be Banach spaces and (formula presented).enhttps://creativecommons.org/licenses/by/4.0/MathematikBook Part10.15480/882.417110.1007/978-3-030-89397-2_210.15480/882.4171Other