Operators and Matrices · Volume 14, Issue 4 Semi-smooth points in space of operators on Hilbert space 14-59 Pages 951-958 DOI 10.7153/oam-2020-14-59 Downloads Short PDF Full PDF PNG Authors Paweł Wójcik Keywords Hilbert space space of operators norm derivatives semi-smoothness Subject classes 46B20 46B28 46C50 47L05