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On fixed points of Lüders operation. (English) Zbl 1283.47056
Summary: In this paper, we give a concrete example of a Lüders operation $$L_A$$ with $$n=3$$, such that $$L_A(B)=B$$ does not imply that $$B$$ commutes with all $$E_1, E_2$$, and $$E_3$$ in $$A$$, this example answers an open problem of Professor Gudder.